{"title":"Gaskets, Seals \u0026 Bearings","description":null,"products":[{"product_id":"sierra-18-0115-powerhead-base-gasket-replaces-27-f307279-2-fits-force-chrysler-125-150-hp-outboards-pack-of-2","title":"Sierra Powerhead Base Gasket 18-0115, Replaces 27-F307279-2, Fits Chrysler\/Force 150 HP 1989-1994","description":"\u003cp\u003eThe Sierra Powerhead Base Gasket, part number 18-0115, seals the joint between the powerhead and the crankcase on covered Chrysler\/Force outboards, sold as a package of two so you have a spare on hand for the next service interval. A properly seated base gasket is essential to maintaining crankcase compression and preventing air or oil leaks at the powerhead mating surface, both of which can cause hard starting, rough idle, or reduced power if the seal fails.\u003c\/p\u003e\u003cp\u003eThis gasket is a direct equivalent to Chrysler\/Force OEM part 27-F307279-2, so it installs in place of the original without modification. It is designed for the Chrysler\/Force 150 HP outboard built in the 1989-1994 model years within serial number range E000001-E093699. Because base gaskets are a wear item that should be replaced any time the powerhead is removed or reseated, keeping the included pair on hand covers both a current job and a future one.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0115\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Powerhead Base Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 2 gaskets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.06 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999750938\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 27-F307279-2\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eChrysler\/Force 150 HP outboard, 1989-1994, serial number range E000001-E093699\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-F307279-2\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0115 powerhead base gasket fit?\u003c\/strong\u003e Sierra part 18-0115 fits the Chrysler\/Force 150 HP outboard built in the 1989-1994 model years, within serial number range E000001-E093699.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in this package?\u003c\/strong\u003e The 18-0115 powerhead base gasket ships as a package of two, giving you a spare for the next time the powerhead is serviced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0115 a direct replacement for the original Chrysler\/Force gasket?\u003c\/strong\u003e Yes, 18-0115 replaces OEM part 27-F307279-2 and installs in the same location without modification.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the OEM part number that 18-0115 replaces?\u003c\/strong\u003e It replaces Chrysler\/Force part number 27-F307279-2.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the powerhead base gasket weigh?\u003c\/strong\u003e Each package of the 18-0115 base gasket weighs 0.06 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0115 gasket?\u003c\/strong\u003e The gasket measures approximately 0.39 x 0.39 x 0.39 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the powerhead base gasket on my Chrysler\/Force outboard?\u003c\/strong\u003e The 18-0115 base gasket should be replaced any time the powerhead is removed or reseated on a compatible Chrysler\/Force 150 HP outboard, since the seal cannot be reused reliably once broken.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if the powerhead base gasket fails?\u003c\/strong\u003e A failed base gasket can allow air or oil leaks at the powerhead-to-crankcase joint, leading to hard starting, rough idle, or reduced power, which is why Sierra part 18-0115 is stocked as a maintenance replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this gasket brand new or a used part?\u003c\/strong\u003e The Sierra 18-0115 powerhead base gasket is a new replacement part, sold in a sealed package of two.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes 18-0115 fit other Chrysler\/Force horsepower models?\u003c\/strong\u003e 18-0115 is specified for the 150 HP Chrysler\/Force outboard within serial range E000001-E093699; other horsepower or serial ranges use a different Sierra part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat UPC is associated with the 18-0115 gasket?\u003c\/strong\u003e The Sierra 18-0115 powerhead base gasket carries UPC 030999750938.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988021784795,"sku":"SIE-18-0115","price":2.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0115_lg_1__65944.1558117768.500.750.jpg?v=1785188279"},{"product_id":"exhaust-cover-gasket-for-evinrude-outboards-replaces-oem-325211-mpn-118-0128","title":"Sierra Powerhead Base Gasket 18-0128 for Evinrude Outboard Motors","description":"\u003cp\u003eThe Sierra 18-0128 Powerhead Base Gasket is a replacement gasket designed for Evinrude outboard motors, seated at the base of the powerhead to help maintain a proper seal during operation. As a base gasket, it is a wear item that should be replaced any time the powerhead is removed or serviced, ensuring the mating surfaces seal correctly when the assembly is reinstalled. It is offered as part of Sierra's lineup of Evinrude outboard gasket sets, giving outboard owners and marine technicians a dedicated Sierra part number to order for this specific application.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0128\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Powerhead Base Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Evinrude Outboard Gasket Sets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999751034\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eEvinrude outboard motors (powerhead base application)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0128?\u003c\/strong\u003e Sierra 18-0128 is a Powerhead Base Gasket made for Evinrude outboard motors, used to seal the base of the powerhead assembly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is this gasket used for?\u003c\/strong\u003e It seals the mating surface at the base of the powerhead on Evinrude outboard motors, and is intended to be replaced whenever the powerhead is removed for service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0128 gasket weigh?\u003c\/strong\u003e The Sierra 18-0128 Powerhead Base Gasket weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat brand of outboard does this gasket fit?\u003c\/strong\u003e This gasket is designed for Evinrude outboard motors and is listed within Sierra's Evinrude outboard gasket sets.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0128 the correct part number to order?\u003c\/strong\u003e Yes, 18-0128 is the Sierra part number for this specific Powerhead Base Gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0128 gasket sold individually?\u003c\/strong\u003e The 18-0128 is listed as the Powerhead Base Gasket itself, within Sierra's category of Evinrude outboard gasket sets.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0128 gasket?\u003c\/strong\u003e The UPC for the Sierra Powerhead Base Gasket, part number 18-0128, is 030999751034.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should the powerhead base gasket be replaced?\u003c\/strong\u003e The Sierra 18-0128 Powerhead Base Gasket should be replaced whenever the powerhead is removed from an Evinrude outboard for service, since the old gasket should not be reused.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0128 gasket include installation instructions?\u003c\/strong\u003e No installation instructions are specified for the Sierra 18-0128 Powerhead Base Gasket; it is supplied as the replacement gasket only.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988022997211,"sku":"SIE-18-0128","price":9.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0128_lg__51106.1558118711.500.750.jpg?v=1785329179"},{"product_id":"sierra-18-0133-water-jacket-cover-gasket-for-mercury-outboards-replaces-oem-27-73665","title":"Sierra Water Jacket Gasket 18-0133, Replaces 27-73665 and 27-52892, for 4 Cylinder Outboards","description":"\u003cp\u003eThe Sierra Water Jacket Gasket, part number 18-0133, seals the water jacket cover on 4 cylinder outboard engines, forming the barrier between the cooling passages and the engine block to prevent coolant leaks and maintain proper cooling system pressure. Correct sealing at this joint is essential to preventing overheating and coolant loss, so this gasket is intended to be replaced any time the water jacket cover is removed for service rather than reused. It is manufactured to the dimensions and fit of the original equipment cover it mates to, measuring 0.39 x 0.39 x 0.39 inches and weighing 0.12 pounds, making it a compact, low-cost component that is easy to keep on hand as routine maintenance stock.\u003c\/p\u003e\u003cp\u003eThis gasket is sold individually (priced per piece). Buyers who need multiple units can order the package of 5 by requesting part number 18-0133-9 instead.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0133\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Water Jacket Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Fitment:\u003c\/strong\u003e 4 Cylinder\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.12 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Sold individually; package of 5 available as 18-0133-9\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 27-73665, 27-52892\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999754950\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e4 Cylinder outboard engines\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e27-73665\u003c\/li\u003e\n\u003cli\u003e27-52892\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0133 gasket fit?\u003c\/strong\u003e The 18-0133 water jacket gasket is designed for 4 cylinder outboard engines, sealing the water jacket cover against the engine block.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0133 a direct replacement for OEM gaskets?\u003c\/strong\u003e Yes, part 18-0133 replaces OEM gaskets 27-73665 and 27-52892, so either original number can be used to confirm this is the correct part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0133 water jacket gasket?\u003c\/strong\u003e This gasket measures 0.39 x 0.39 x 0.39 inches, a compact size consistent with a water jacket cover seal on a 4 cylinder outboard.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0133 gasket weigh?\u003c\/strong\u003e The Sierra 18-0133 water jacket gasket weighs 0.12 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I buy the 18-0133 gasket in a multi-pack?\u003c\/strong\u003e The base part 18-0133 is sold individually (priced per piece); for a package of 5, order part number 18-0133-9 instead.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShould the water jacket gasket be reused after removing the cover?\u003c\/strong\u003e No, a water jacket gasket like the 18-0133 should be replaced with a new one any time the water jacket cover is removed, since a reused gasket is prone to leaking.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if the water jacket gasket fails?\u003c\/strong\u003e A failed water jacket gasket, such as an old or damaged 18-0133, can allow coolant to leak from the water jacket cover joint, leading to reduced cooling efficiency or overheating.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes Sierra 18-0133 cross-reference to more than one OEM number?\u003c\/strong\u003e Yes, 18-0133 corresponds to two OEM numbers, 27-73665 and 27-52892, both of which it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0133 gasket genuine Sierra or aftermarket equivalent?\u003c\/strong\u003e The 18-0133 is a Sierra brand part manufactured as a direct-fit replacement for the listed OEM numbers on 4 cylinder outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order part 18-0133?\u003c\/strong\u003e An order of 18-0133 includes one water jacket gasket; if the package quantity of 5 is needed, request part 18-0133-9 instead.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988023193819,"sku":"SIE-18-0133","price":5.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0133_lg__43565.1558119003.500.750.jpg?v=1785189212"},{"product_id":"evinrude-johnson-air-box-gasket-mpn-118-0140-outboard-gasket","title":"Sierra Air Box Gasket 18-0140 for Evinrude Outboard Engines","description":"\u003cp\u003eThe Sierra 18-0140 Air Box Gasket is a replacement seal designed for Evinrude outboard engines, sold as part of Sierra's outboard gasket set lineup. It is installed between the air box housing and the engine intake to maintain a proper seal, preventing unmetered air, dirt, and moisture from entering the intake tract and disrupting the air\/fuel mixture. A worn, cracked, or compressed air box gasket can cause a rough idle, hesitation, or an inconsistent fuel mixture, so replacing it during routine maintenance or when servicing the air box helps restore a proper seal.\u003c\/p\u003e\u003cp\u003eThis gasket is lightweight at 0.03 pounds and is identified by UPC 030999751102 and Sierra part number 18-0140. It is intended as a direct-fit replacement for the factory air box gasket on applicable Evinrude outboard engines, making it a straightforward maintenance item to keep on hand for outboard servicing.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0140\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Air Box Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Evinrude Outboard Engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999751102\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.03 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits applicable Evinrude outboard engines. Confirm compatibility with your engine's air box before ordering.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cp\u003eNo OEM cross-reference numbers are specified for this part.\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0140 air box gasket fit?\u003c\/strong\u003e The 18-0140 is designed for Evinrude outboard engines and is meant to be installed as a seal between the air box housing and the engine intake.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0140 a genuine Sierra part number?\u003c\/strong\u003e Yes, 18-0140 is the Sierra manufacturer part number for this air box gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does this gasket weigh?\u003c\/strong\u003e The 18-0140 air box gasket weighs 0.03 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for this part?\u003c\/strong\u003e The UPC for the Sierra 18-0140 air box gasket is 030999751102.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the air box gasket installed?\u003c\/strong\u003e It seals the joint between the air box housing and the intake on the outboard engine, preventing unmetered air, dirt, and moisture from entering the intake.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the symptoms of a failing air box gasket?\u003c\/strong\u003e A cracked or compressed air box gasket like the 18-0140 can allow unmetered air into the intake, which may cause a rough idle, hesitation, or an inconsistent air\/fuel mixture.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eAre OEM cross-reference numbers available for this gasket?\u003c\/strong\u003e No OEM cross-reference numbers are listed for the Sierra 18-0140 air box gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this gasket sold individually or as part of a set?\u003c\/strong\u003e The 18-0140 is offered as an individual air box gasket within Sierra's outboard gasket set category.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the air box gasket?\u003c\/strong\u003e Replace the 18-0140 air box gasket any time the gasket is visibly worn, cracked, or compressed, or when servicing the air box on an Evinrude outboard.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this gasket require any special tools to install?\u003c\/strong\u003e The 18-0140 is a standard flat gasket that is installed by removing the air box housing and fitting the new gasket in place of the old one.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988025323739,"sku":"SIE-18-0140","price":2.64,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0140_lg__78072.1558119612.500.750.jpg?v=1785329149"},{"product_id":"bypass-gasket-for-chrysler-force-outboard-100-140-hp-replaces-oem-27-f85762-2-pack-mpn-118-0141-9","title":"Sierra Bypass Gasket 18-0141-9, 2-Pack, Force Outboard Powerhead Gasket","description":"\u003cp\u003eThe Sierra 18-0141-9 bypass gasket is a powerhead gasket engineered for Force outboard engines, sold as a 2-pack so a spare is always on hand for the next service interval. Bypass gaskets like this one seal the bypass passage on the powerhead, helping maintain proper sealing between mating surfaces during engine operation. Each pack is lightweight at just 0.01 pounds, reflecting its role as a precision-cut sealing component rather than a bulky assembly. Ordering the correct Sierra part number ensures the gasket matches the dimensions and bolt pattern of the original equipment it is designed to seal, which is important for preventing leaks and maintaining compression or fluid pathways within the powerhead. Because it ships two to a pack, boat owners and marine technicians can complete a full gasket replacement or keep a spare on the shelf without ordering twice. This gasket is cataloged under Sierra's Force Outboard Powerhead Gaskets line, making it easy to identify alongside other powerhead sealing components for the same engine family.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0141-9\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Category:\u003c\/strong\u003e Force Outboard Powerhead Gaskets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 2 gaskets per pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282161408\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in a Sierra 18-0141-9 pack?\u003c\/strong\u003e Two bypass gaskets ship in every pack of Sierra part number 18-0141-9, so a spare is included with each order.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0141-9 used for?\u003c\/strong\u003e It is a bypass gasket for the powerhead of Force outboard engines, used to seal the bypass passage during engine operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0141-9 bypass gasket weigh?\u003c\/strong\u003e 0.01 pounds per pack, reflecting its size as a thin, precision-cut sealing gasket rather than a bulky part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category does this gasket fall under?\u003c\/strong\u003e Sierra catalogs the 18-0141-9 under its Force Outboard Powerhead Gaskets line.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0141-9 sold individually or in a pack?\u003c\/strong\u003e It is sold per 2-pack, not as a single gasket, under Sierra part number 18-0141-9.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0141-9 gasket?\u003c\/strong\u003e 808282161408 is the UPC associated with the Sierra 18-0141-9 bypass gasket 2-pack.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0141-9 a genuine Sierra Marine part number?\u003c\/strong\u003e Yes, 18-0141-9 is the Sierra part number for this bypass gasket, identifying it within Sierra's Force outboard powerhead gasket lineup.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShould I replace both gaskets at once when servicing the powerhead?\u003c\/strong\u003e Since the Sierra 18-0141-9 ships as a 2-pack, both gaskets are available in a single order, making it convenient to replace them together during a service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0141-9 include installation hardware?\u003c\/strong\u003e The pack contains the bypass gaskets themselves (two per pack); no additional hardware is specified for this part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy order a spare Sierra 18-0141-9 gasket?\u003c\/strong\u003e Because bypass gaskets are used during powerhead service and can be damaged during removal, having the second gasket from the 2-pack on hand avoids a delay in completing the job.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988026732763,"sku":"SIE-18-0141-9","price":1.48,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0141_lg__13581.1558119741.500.750.jpg?v=1785329152"},{"product_id":"sierra-18-0172-oil-seal-for-mercury-mariner-outboards-replaces-oem-26-97530","title":"Sierra Oil Seal 18-0172, Replaces Mercruiser 26-97530, 0.845 Inch Shaft","description":"\u003cp\u003eThe Sierra 18-0172 Oil Seal is a round oil seal engineered as a direct replacement for the Mercruiser 26-97530. It is designed to maintain a reliable barrier against oil and water intrusion at the shaft, keeping lubricants contained and contaminants out for dependable operation. Sierra manufactures this seal to meet or exceed the specifications of the original equipment part it replaces, so it installs and performs the same way as the part it is replacing. The seal features a round profile with a white finish and is sized precisely to a 0.845 inch shaft diameter, 1.500 inch outer diameter, and 0.315 inch width, ensuring a proper fit without modification. This is a single-unit component, sold individually, making it a straightforward swap when servicing a worn or leaking seal. Because it carries the Sierra part number 18-0172 and matches the Mercruiser 26-97530 cross-reference, it is easy to identify and order the correct replacement without guesswork. Marine technicians and boat owners performing routine maintenance or repair on applicable Mercruiser equipment can rely on this seal to restore proper sealing function at the shaft.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0172\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.845 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.500 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.315 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.03 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999751300\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eInterchangeable with Mercruiser 26-97530.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-97530\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0172 Oil Seal replace?\u003c\/strong\u003e The Sierra 18-0172 Oil Seal is interchangeable with Mercruiser 26-97530, so it can be ordered as a direct replacement for that part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the shaft size on this oil seal?\u003c\/strong\u003e The shaft size is 0.845 inches on the Sierra 18-0172 Oil Seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the outer diameter and width of the 18-0172 seal?\u003c\/strong\u003e The outer diameter is 1.500 inches and the width is 0.315 inches on the Sierra 18-0172 Oil Seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0172 a genuine Mercruiser part or an aftermarket equivalent?\u003c\/strong\u003e It is a Sierra-manufactured seal, not a Mercruiser-branded part, but Sierra makes it to meet or exceed the specifications of the Mercruiser 26-97530 it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape and color is this oil seal?\u003c\/strong\u003e The Sierra 18-0172 Oil Seal has a round shape and a white finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many seals are included when I order the 18-0172?\u003c\/strong\u003e One unit is included per order of the Sierra 18-0172 Oil Seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0172 Oil Seal weigh?\u003c\/strong\u003e It weighs 0.03 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the Sierra 18-0172 seal fit in place of a worn factory seal without modification?\u003c\/strong\u003e Yes, because it is dimensionally matched to the Mercruiser 26-97530 it replaces, the Sierra 18-0172 installs in place of the original seal without modification.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0172 Oil Seal?\u003c\/strong\u003e The UPC is 030999751300 for the Sierra 18-0172 Oil Seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes Sierra warranty the 18-0172 Oil Seal?\u003c\/strong\u003e Yes, the Sierra 18-0172 Oil Seal is covered under Sierra's limited warranty.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988027322587,"sku":"SIE-18-0172","price":13.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0172_lg__91673.1558118066.500.750.jpg?v=1785189080"},{"product_id":"sierra-18-0184-rubber-ring-for-volvo-penta-reverse-tilt-lock-replaces-804190-fits-sp-a-dp-a-aq250-290-sterndrives","title":"Sierra Rubber Ring 18-0184, Replaces 804190, Clamp Ring Seal for Volvo Penta SP-A\/DP-A\/DP-B Drives and AQ Series Engines","description":"\u003cp\u003eThe Sierra Rubber Ring, part number 18-0184, is a clamp ring seal used on Volvo Penta sterndrive units and inboard engines. It is a direct replacement for OEM number 804190, allowing it to be installed anywhere that original ring was specified without modification. The ring is made of white rubber, shaped to seat against the clamp ring where the drive leg joins the transom assembly or where the engine-side clamp ring is fitted, helping maintain a sealed connection at that joint.\u003c\/p\u003e\u003cp\u003eThis ring fits Volvo Penta drive legs including 275A, 280, 280DP, 280L, 285A, 290, 290A, 290DP, SP-A, SP-A\/MT, SP-A1, SP-A2, DP-A, DP-A1, DP-A2, DP-B, and DP-B1. The same clamp ring design is also used on a wide range of AQ-series engines, so 18-0184 additionally fits 230A\/SP-A\/MT, 250A\/SP-A\/MT, 500A, 501A, 571A, 740A, AQ100, AQ105, AQ110, AQ115A, AQ110B, AQ120A, AQ120B, AQ125A\/B, AQ130A\/B, AQ131A\/D, AQ175A, AQ190A, AQ200A\/C\/D\/F, AQ210A, AQ211A, AQ225A\/B\/C\/D\/E\/F, AQ231A\/B, AQ240A, AQ255A\/B, AQ260A\/B, AQ271A\/B\/C\/D, AQ280A, AQ290A, AQ311A\/B, AQ60F, AQ80, AQ90, AQ95, AQD19, AQD29\/A, and AQD32A. Each unit ships as a single ring weighing 0.57 pounds. Confirm your drive or engine model against this fitment list before ordering, since Sierra also offers a separate rubber ring, 18-8368, for a different clamp ring range.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0184\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Rubber Ring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Rubber\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.57 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1 ring per package\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282188641\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 804190\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eVolvo Penta drive legs: 275A, 280, 280DP, 280L, 285A, 290, 290A, 290DP, SP-A, SP-A\/MT, SP-A1, SP-A2, DP-A, DP-A1, DP-A2, DP-B, DP-B1\u003c\/li\u003e\n\u003cli\u003eClamp ring fits: 230A\/SP-A\/MT, 250A\/SP-A\/MT, 500A, 501A, 571A, 740A, AQ100, AQ105, AQ110, AQ115A, AQ110B, AQ120A, AQ120B, AQ125A\/B, AQ130A\/B, AQ131A\/D, AQ175A, AQ190A, AQ200A\/C\/D\/F, AQ210A, AQ211A, AQ225A\/B\/C\/D\/E\/F, AQ231A\/B, AQ240A, AQ255A\/B, AQ260A\/B, AQ271A\/B\/C\/D, AQ280A, AQ290A, AQ311A\/B, AQ60F, AQ80, AQ90, AQ95, AQD19, AQD29\/A, AQD32A\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e804190\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does Sierra Rubber Ring 18-0184 replace?\u003c\/strong\u003e Part number 18-0184 replaces OEM number 804190, so it installs as a direct equivalent anywhere that original clamp ring seal was specified.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich Volvo Penta drive legs use this clamp ring?\u003c\/strong\u003e The 18-0184 rubber ring fits clamp rings on 275A, 280, 280DP, 280L, 285A, 290, 290A, and 290DP drive legs, as well as SP-A, SP-A\/MT, SP-A1, SP-A2, DP-A, DP-A1, DP-A2, DP-B, and DP-B1 legs.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0184 ring fit engines as well as drive legs?\u003c\/strong\u003e Yes, the clamp ring sealed by this ring also fits AQ-series engines including AQ100, AQ105, AQ110, AQ115A, AQ110B, AQ120A\/B, AQ125A\/B, AQ130A\/B, AQ131A\/D, AQ175A, AQ190A, AQ200A\/C\/D\/F, AQ210A, AQ211A, AQ225A\/B\/C\/D\/E\/F, AQ231A\/B, AQ240A, AQ255A\/B, AQ260A\/B, AQ271A\/B\/C\/D, AQ280A, AQ290A, and AQ311A\/B, plus 230A\/SP-A\/MT, 250A\/SP-A\/MT, 500A, 501A, 571A, 740A, AQ60F, AQ80, AQ90, AQ95, AQD19, AQD29\/A, and AQD32A.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0184 ring made of?\u003c\/strong\u003e It is a rubber ring, sized to seat against the clamp ring on compatible Volvo Penta drive legs and AQ-series engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0184 rubber ring?\u003c\/strong\u003e The 18-0184 rubber ring is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does part number 18-0184 weigh?\u003c\/strong\u003e The Sierra 18-0184 rubber ring weighs 0.57 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many rings are included when ordering 18-0184?\u003c\/strong\u003e Each package of Sierra part 18-0184 contains one rubber ring.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0184 a genuine Sierra part or a generic aftermarket seal?\u003c\/strong\u003e 18-0184 is a Sierra-branded rubber ring engineered to replace OEM number 804190, rather than a generic universal seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the difference between Sierra 18-0184 and 18-8368?\u003c\/strong\u003e Sierra 18-0184 replaces OEM 804190 and fits clamp rings on 275A\/280\/290-series drive legs and AQ100 through AQ311A\/B engines, while Sierra 18-8368 is a separate rubber ring that replaces OEM 813967 and fits a different clamp ring range including 230A\/SP-A\/SP A1, 230B, 250A\/B, 251A, 430A\/B, 431A\/B, 432A, 434A, 500B, 501B, 570A, and 572A. Match your drive or engine model to the correct part before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I confirm 18-0184 is the correct ring for my drive or engine?\u003c\/strong\u003e Check your model against the 18-0184 fitment list, which covers 275A, 280, 280DP, 280L, 285A, 290, 290A, 290DP, SP-A, SP-A\/MT, SP-A1, SP-A2, DP-A, DP-A1, DP-A2, DP-B, DP-B1, and the AQ-series engines listed for its clamp ring; if your model is not on that list, a different Sierra rubber ring such as 18-8368 may be the correct part instead.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988055240923,"sku":"SIE-18-0184","price":35.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0184_lg__99246.1558118790.500.750.jpg?v=1785188306"},{"product_id":"marine-engine-washer-92990-10600-00-for-yamaha-225-hp-outboard-1992-1993-1997-sierra-18-0192","title":"Sierra Washer 18-0192, Replaces Yamaha 92901-10600-00, 92902-10600-00, 92903-10600-00","description":"\u003cp\u003eThe Sierra 18-0192 is a marine engine washer designed as a direct replacement for the Yamaha OEM washers listed below. It is used during outboard engine service and reassembly to provide a proper seating surface at fastener and fitting points, helping maintain a secure, even fit where these Yamaha OEM washers are called for. Priced and sold per piece, it is a small but important part to have on hand for engine maintenance and repair jobs.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0192\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Engine Parts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.15 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282291839\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold As:\u003c\/strong\u003e Priced per piece\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eDesigned to fit applications using Yamaha OEM washers 92901-10600-00, 92902-10600-00, and 92903-10600-00\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eYamaha 92901-10600-00\u003c\/li\u003e\n\u003cli\u003eYamaha 92902-10600-00\u003c\/li\u003e\n\u003cli\u003eYamaha 92903-10600-00\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0192 washer used for?\u003c\/strong\u003e The Sierra 18-0192 is an engine washer used during outboard engine service and reassembly at points where the corresponding Yamaha OEM washer is specified.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich Yamaha OEM part numbers does the Sierra 18-0192 replace?\u003c\/strong\u003e It replaces three Yamaha OEM numbers: 92901-10600-00, 92902-10600-00, and 92903-10600-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0192 a genuine Yamaha part or an aftermarket replacement?\u003c\/strong\u003e The 18-0192 is a Sierra-branded aftermarket washer manufactured to replace the Yamaha OEM washers 92901-10600-00, 92902-10600-00, and 92903-10600-00, not a Yamaha-branded original part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0192 washer weigh?\u003c\/strong\u003e This washer weighs 0.15 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0192 sold individually or in a set?\u003c\/strong\u003e The 18-0192 washer is priced and sold per piece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill one Sierra 18-0192 washer work in place of any of the three listed Yamaha numbers?\u003c\/strong\u003e Yes, the Sierra 18-0192 is a single part that cross-references to all three Yamaha OEM numbers: 92901-10600-00, 92902-10600-00, and 92903-10600-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of part is the Sierra 18-0192?\u003c\/strong\u003e The 18-0192 is classified as an engine parts item, specifically a washer used in outboard engine assemblies.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if I need the Sierra 18-0192 washer for my engine?\u003c\/strong\u003e If your Yamaha engine calls for OEM washer 92901-10600-00, 92902-10600-00, or 92903-10600-00, the Sierra 18-0192 is the matching replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0192 come with any other hardware?\u003c\/strong\u003e The 18-0192 listing is for the washer only, priced per piece, with no additional hardware included.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988056715483,"sku":"SIE-18-0192","price":0.94,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0192__32942.1558184442.500.750.jpg?v=1785329190"},{"product_id":"sierra-18-0203-9-bell-housing-washer-replaces-mercruiser-12-35935-fits-all-mercruiser-sterndrives-1963-1998-pack-of-5","title":"Sierra 18-0203-9 Bell Housing Washer, Replaces Mercruiser 12-29395, Fits Sterndrives 1963-1998, Pack of 5","description":"\u003cp\u003eThe Sierra 18-0203-9 Bell Housing Washer is a brass conical spring washer designed for use at the bell housing joint on Mercruiser sterndrive units. It is sold in a package of 5, matching the quantity typically needed for a bell housing service or rebuild job. The conical spring design allows the washer to provide consistent seating pressure at the fastener location, helping maintain a secure, properly torqued connection during reassembly.\u003c\/p\u003e\u003cp\u003eBuilt from brass, the washer resists corrosion in the marine environment better than uncoated steel alternatives, which matters given its location near the drive unit and exposure to bilge moisture and saltwater spray. Each washer measures 0.39 x 0.39 x 0.39 inches. The Sierra 18-0203-9 is intended as a direct equivalent for the original equipment washer it replaces, so it installs using the same fasteners and orientation as the factory part with no modification required.\u003c\/p\u003e\u003cp\u003eThis washer fits all Mercruiser sterndrives from 1963 to 1998, making it a common replacement part for owners doing bell housing maintenance, gasket replacement, or a full drive service on older Mercruiser-powered boats. Because it is sold in a 5-pack, it is priced and packaged for a complete job rather than a single washer replacement.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0203-9\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Bell Housing Washer\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Brass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWasher Type:\u003c\/strong\u003e Conical Spring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Brass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePack Quantity:\u003c\/strong\u003e 5\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.05 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282166816\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eAll Mercruiser sterndrives, 1963-1998\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e12-29395\u003c\/li\u003e\n\u003cli\u003e12-8M0042641\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0203-9 washer fit?\u003c\/strong\u003e The Sierra 18-0203-9 Bell Housing Washer fits all Mercruiser sterndrives from 1963 to 1998.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many washers come in a pack?\u003c\/strong\u003e The 18-0203-9 is sold in a package of 5 brass bell housing washers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does this washer replace?\u003c\/strong\u003e Sierra 18-0203-9 replaces OEM numbers 12-29395 and 12-8M0042641.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the bell housing washer made from?\u003c\/strong\u003e It is made from brass, which resists corrosion better than uncoated steel in a marine bilge environment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size is the Sierra 18-0203-9 washer?\u003c\/strong\u003e Each washer in the 18-0203-9 pack measures 0.39 x 0.39 x 0.39 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat type of washer is this?\u003c\/strong\u003e The 18-0203-9 is a conical spring washer, which provides consistent seating pressure at the bell housing fastener.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0203-9 an aftermarket or genuine Mercruiser part?\u003c\/strong\u003e It is a Sierra aftermarket washer manufactured to be a direct equivalent to the original Mercruiser bell housing washer it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0203-9 washer pack weigh?\u003c\/strong\u003e The full package of 5 Sierra 18-0203-9 washers weighs 0.05 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need a full pack of 5 for a bell housing job?\u003c\/strong\u003e The 18-0203-9 is packaged in quantities of 5 to match a typical bell housing service, though exact usage depends on the specific job.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this washer work on a Mercruiser from the 2000s?\u003c\/strong\u003e The Sierra 18-0203-9 is specified for Mercruiser sterndrives from 1963 to 1998; fitment outside that range is not confirmed for this part.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988057960667,"sku":"SIE-18-0203-9","price":12.64,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0203_lg__56485.1558119673.500.750.jpg?v=1785187970"},{"product_id":"sierra-18-0232-cover-gasket-replaces-mercury-27-703351-fits-3-cylinder-outboards-package-of-2","title":"Sierra Cover Gasket 18-0232 for Yamaha Outboard Engines, Replaces 27-81031M","description":"\u003cp\u003eThe Sierra 18-0232 is a cover gasket built for Yamaha outboard engines. It seals the mating surface between the engine cover and the block, preventing oil, coolant, or air leaks at that joint and helping the covered components run reliably. As a direct-fit replacement, it is engineered to match the exact profile and thickness of the original equipment gasket it replaces, so it installs without modification and restores a proper seal after the old gasket has hardened, torn, or compressed with age.\u003c\/p\u003e\u003cp\u003eThis gasket is manufactured by Sierra, a long-established supplier of marine engine parts, and is cross-referenced to the OEM Yamaha part number it replaces. It ships as a single gasket and is lightweight at just 0.01 pounds, reflecting its thin, flat construction typical of cover gaskets. Because gaskets are wear items that lose their sealing ability once removed or over time, keeping a replacement like the 18-0232 on hand makes routine cover maintenance straightforward.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0232\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Cover Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e Yamaha outboard engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplaces (OEM):\u003c\/strong\u003e 27-81031M\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Items:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999973788\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGTIN:\u003c\/strong\u003e 00030999973788\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for Yamaha outboard engines.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cp\u003e27-81031M\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0232 cover gasket fit?\u003c\/strong\u003e The Sierra 18-0232 cover gasket is designed for Yamaha outboard engines and installs in place of the original cover gasket without modification.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0232 replace OEM part 27-81031M?\u003c\/strong\u003e Yes, the Sierra 18-0232 is a direct replacement for OEM Yamaha part 27-81031M and is built to the same fit and seal profile.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0232 cover gasket weigh?\u003c\/strong\u003e The Sierra 18-0232 cover gasket weighs 0.01 pounds, consistent with its thin, flat gasket construction.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0232 sold as a single gasket or in a multi-pack?\u003c\/strong\u003e The Sierra 18-0232 is sold as a single cover gasket, with one item per package.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0232 cover gasket?\u003c\/strong\u003e The UPC for the Sierra 18-0232 cover gasket is 030999973788, with a corresponding GTIN of 00030999973788.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does a cover gasket like the 18-0232 actually do?\u003c\/strong\u003e A cover gasket seals the joint between an engine cover and the block it mounts to, preventing leaks at that surface; the 18-0232 performs this function on applicable Yamaha outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0232 an OEM part or an aftermarket replacement?\u003c\/strong\u003e The 18-0232 is a Sierra aftermarket gasket manufactured to replace OEM Yamaha part 27-81031M, not an OEM-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should the 18-0232 cover gasket be replaced?\u003c\/strong\u003e A cover gasket such as the 18-0232 should be replaced any time the cover it seals is removed, or if it shows signs of hardening, tearing, or leaking.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-0232 gasket be reused after removal?\u003c\/strong\u003e No, cover gaskets including the 18-0232 are designed for one-time use and should be replaced with a new gasket any time the cover is taken off.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat comes in the package with the Sierra 18-0232?\u003c\/strong\u003e The package contains one Sierra 18-0232 cover gasket and no additional hardware or components.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988059730139,"sku":"SIE-18-0232","price":1.67,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0232_lg__04249.1558118069.500.750.jpg?v=1785188635"},{"product_id":"sierra-18-0320-reed-block-gasket-for-mercury-outboards-replaces-mercury-27-13937-27-139374","title":"Sierra 18-0320 Reed Block Gasket - Cross Reference Mercury 27-13937","description":"\u003cp\u003eThe Sierra 18-0320 is a reed block gasket built for outboard engine service, sealing the mating surface between the reed valve block and the powerhead to maintain proper crankcase compression and prevent air or fuel leaks at the joint. It is manufactured from a glass-based gasket material designed to hold a consistent seal under the heat cycling and vibration typical of outboard operation. Each Sierra gasket is engineered to meet or exceed the quality of the original equipment part it replaces, making it a straightforward direct-fit replacement during a reed block rebuild, powerhead service, or routine maintenance. The 18-0320 is a single-piece gasket supplied as one unit, sized to match the reed block gasket used across a range of Mercury outboard applications that call for this specific part. Because it corresponds to several historical OEM and aftermarket part numbers, it is commonly sourced as a replacement whenever an older reference number is found stamped on the block or listed in a parts diagram. Installers should confirm the old gasket's dimensions and bolt pattern against the 18-0320 before ordering, and always install a new gasket rather than reusing the old one to ensure a proper seal.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0320\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Type:\u003c\/strong\u003e Reed Block Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Glass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Multi-coloured\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1 gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999873101\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e GLM 32220, Mallory 9-60061, Mercury 27-13937-6, 27-139374, 27-139372, 27-13937\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 32220\u003c\/li\u003e\n\u003cli\u003eMallory 9-60061\u003c\/li\u003e\n\u003cli\u003eMercury 27-13937-6\u003c\/li\u003e\n\u003cli\u003eMercury 27-139374\u003c\/li\u003e\n\u003cli\u003eMercury 27-139372\u003c\/li\u003e\n\u003cli\u003eMercury 27-13937\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0320 used for?\u003c\/strong\u003e The Sierra 18-0320 is a reed block gasket that seals the joint between the reed valve block and the powerhead on applicable outboard engines, maintaining proper crankcase sealing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0320 gasket the same as Mercury 27-13937?\u003c\/strong\u003e Yes, the Sierra 18-0320 Reed Block Gasket is a direct cross-reference for Mercury 27-13937, 27-13937-6, 27-139374, and 27-139372, along with GLM 32220 and Mallory 9-60061.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0320 reed block gasket made from?\u003c\/strong\u003e It is made from a glass-based gasket material designed to hold a consistent seal under engine heat and vibration.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets are included with part number 18-0320?\u003c\/strong\u003e One reed block gasket is included per unit count for the Sierra 18-0320.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0320 gasket weigh?\u003c\/strong\u003e It weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0320 meet original equipment quality?\u003c\/strong\u003e Sierra states this gasket meets or exceeds the quality of the original equipment part it replaces, making the 18-0320 a reliable equivalent to OEM.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I reuse my old reed block gasket instead of installing the 18-0320?\u003c\/strong\u003e No, a gasket should not be reused once removed; installing a new Sierra 18-0320 ensures a proper seal at the reed block joint.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-0320 gasket?\u003c\/strong\u003e The gasket has a multi-coloured appearance, consistent with its glass-based gasket material.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0320 an aftermarket or genuine Mercury part?\u003c\/strong\u003e The 18-0320 is a Sierra-brand aftermarket gasket engineered as a cross-reference equivalent to the Mercury 27-13937 series parts, not a Mercury-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0320 reed block gasket?\u003c\/strong\u003e The UPC is 030999873101.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988062777563,"sku":"SIE-18-0320","price":3.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0320_lg__55148.1637358372.500.750.jpg?v=1785188626"},{"product_id":"sierra-18-0333-powerhead-base-gasket-replaces-mercury-mariner-27-39401-fits-mercury-mariner-outboards","title":"Sierra Powerhead Base Gasket 18-0333, Replaces Mercury 27-39401, Fits Mercury\/Mariner Outboard Motors","description":"\u003cp\u003eThe Sierra 18-0333 is a powerhead base gasket engineered as a direct replacement for Mercury Marine part number 27-39401. It is designed to fit Mercury and Mariner outboard motors, sealing the joint between the powerhead and the driveshaft housing to maintain proper compression and prevent water or exhaust leakage at this critical junction. A powerhead base gasket is a wear item that should be replaced any time the powerhead is removed for service, since reusing an old gasket can compromise the seal and lead to leaks or reduced performance.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0333\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Powerhead Base Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.05 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999873224\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMercury outboard motors\u003c\/li\u003e\n\u003cli\u003eMariner outboard motors\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-39401\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0333 gasket fit?\u003c\/strong\u003e The Sierra 18-0333 powerhead base gasket is designed to fit Mercury and Mariner outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does 18-0333 replace?\u003c\/strong\u003e It replaces Mercury Marine part number 27-39401.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0333 gasket the same as the OEM 27-39401 part?\u003c\/strong\u003e Yes, the Sierra 18-0333 is built to replace Mercury Marine 27-39401 as a direct equivalent for the powerhead base seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0333 gasket weigh?\u003c\/strong\u003e The 18-0333 powerhead base gasket weighs 0.05 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the powerhead base gasket installed?\u003c\/strong\u003e The 18-0333 is installed at the base of the powerhead, sealing the joint between the powerhead and the driveshaft housing on Mercury and Mariner outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the powerhead base gasket?\u003c\/strong\u003e The 18-0333 should be replaced any time the powerhead is removed from the driveshaft housing for service, since reusing the old gasket can result in a poor seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0333 gasket work on Mariner-branded outboards?\u003c\/strong\u003e Yes, the 18-0333 is designed to fit both Mercury and Mariner outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0333 gasket?\u003c\/strong\u003e The Sierra 18-0333 powerhead base gasket carries UPC 030999873224.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0333 a genuine Sierra part or a generic gasket?\u003c\/strong\u003e The 18-0333 is a Sierra-branded powerhead base gasket manufactured to replace Mercury Marine 27-39401.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-0333?\u003c\/strong\u003e Ordering the 18-0333 gets you one Sierra powerhead base gasket sized to replace Mercury Marine 27-39401.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988065005787,"sku":"SIE-18-0333","price":2.71,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0333_lg__93019.1558121069.500.750.jpg?v=1785188228"},{"product_id":"sierra-18-0334-mounting-plate-to-driveshaft-housing-gasket-for-mercury-outboards-replaces-27-39402","title":"Sierra Mounting Plate to Driveshaft Housing Gasket 18-0334 for Mercury Outboards","description":"\u003cp\u003eThe Sierra 18-0334 is a mounting plate to driveshaft housing gasket designed for Mercury outboard motor applications. This gasket seats between the mounting plate and the driveshaft housing to form a tight, reliable seal at that joint, helping keep water out and lubricants in as the lower unit assembly operates. Replacing a worn, cracked, or compressed gasket at this location during a lower unit rebuild, driveshaft housing removal, or general maintenance service helps restore the original factory seal and prevents water intrusion that can lead to corrosion or gearcase damage over time.\u003c\/p\u003e\u003cp\u003eSierra manufactures this gasket to match the fit and function of the original equipment part it replaces, making it a straightforward drop-in choice when servicing the mounting plate and driveshaft housing area on a Mercury outboard. The part ships as a single gasket, part number 18-0334, and is sold individually for one repair.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0334\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Mounting Plate to Driveshaft Housing Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.09 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 gasket per package\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999873231\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury outboard motors (mounting plate to driveshaft housing joint)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0334 gasket used for?\u003c\/strong\u003e The Sierra 18-0334 is a mounting plate to driveshaft housing gasket that seals the joint between the mounting plate and the driveshaft housing on a Mercury outboard motor, helping prevent water intrusion at that connection.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this gasket fit Mercury outboards?\u003c\/strong\u003e Yes, part number 18-0334 is designed for the mounting plate to driveshaft housing joint on Mercury outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in one package?\u003c\/strong\u003e One Sierra 18-0334 gasket is included per package, sold individually for a single repair or rebuild.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0334 gasket weigh?\u003c\/strong\u003e The Sierra 18-0334 mounting plate to driveshaft housing gasket weighs 0.09 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0334 a genuine OEM part or an aftermarket replacement?\u003c\/strong\u003e 18-0334 is manufactured by Sierra as a replacement part designed to match the fit and function of the original mounting plate to driveshaft housing gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen would I need to replace this gasket?\u003c\/strong\u003e This gasket should be replaced any time the mounting plate or driveshaft housing is removed for service, or if the existing gasket is torn, cracked, or compressed and no longer sealing properly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if this gasket fails or is left out during reassembly?\u003c\/strong\u003e A failed or missing gasket at the mounting plate to driveshaft housing joint can allow water to enter the lower unit area, which can lead to corrosion or damage to internal components over time.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan this gasket be reused after removal?\u003c\/strong\u003e Gaskets like the Sierra 18-0334 are designed for one-time use; once the mounting plate or driveshaft housing has been separated, installing a new gasket such as this one is recommended to maintain a proper seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0334 gasket made from?\u003c\/strong\u003e Sierra part 18-0334 is a gasket designed to seal the mounting plate to driveshaft housing joint on Mercury outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs installation of the 18-0334 gasket straightforward?\u003c\/strong\u003e Yes, the Sierra 18-0334 is a direct-fit gasket that installs between the mounting plate and driveshaft housing during reassembly, following standard gasket installation practice for that joint.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988065333467,"sku":"SIE-18-0334","price":3.59,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0334_lg__19203.1558121129.500.750.jpg?v=1785188820"},{"product_id":"sierra-18-0347-valve-cover-gasket-for-mercruiser-470-3-7l-4-cyl-replaces-27-52145-omc-3852693","title":"Sierra Valve Stem Seals (8) 18-0347, Replaces Mercruiser 27-52145, for 4 Cyl. 3.7L Mercruiser 470","description":"\u003cp\u003eThe Sierra 18-0347 is a set of 8 valve stem seals engineered to restore proper oil control at the valve guides on the 4 cyl. 3.7L Mercruiser 470 engine. Valve stem seals wear out over time from heat cycling and contact with the valve stem, letting oil seep down into the combustion chamber or exhaust port; a worn set is a common cause of blue exhaust smoke, fouled plugs, and gradual oil consumption. Sierra manufactures this seal set to meet or exceed original equipment quality, so it installs the same way the original seals did and restores factory sealing performance.\u003c\/p\u003e\u003cp\u003eThis is a set of 8 seals, enough for a complete single-engine valve stem seal replacement job on the applicable Mercruiser 470 engine. Each unit weighs 0.19 pounds. Sierra part number 18-0347 cross-references directly to the Mercury Marine, OMC, GLM, Mallory, and Volvo Penta part numbers listed below, so it is a straightforward like-for-like replacement whether the engine currently carries an original Mercury\/OMC seal or a prior aftermarket equivalent.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0347\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Valve Stem Seals\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 8 seals per set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.19 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282257347\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Fitment:\u003c\/strong\u003e 4 cyl. 3.7L Mercruiser 470\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e Mercury Marine 27-52145, 27-806452, 27-34041; OMC 913277, 912981, 3852693; Volvo Penta 3852693; GLM 32210; Mallory 9-61317\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e4 cyl. 3.7L Mercruiser 470\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 32210\u003c\/li\u003e\n\u003cli\u003eMallory 9-61317\u003c\/li\u003e\n\u003cli\u003eMercruiser 27-52145\u003c\/li\u003e\n\u003cli\u003eMercruiser 27-806452\u003c\/li\u003e\n\u003cli\u003eMercruiser 27-34041\u003c\/li\u003e\n\u003cli\u003eOMC 913277\u003c\/li\u003e\n\u003cli\u003eOMC 912981\u003c\/li\u003e\n\u003cli\u003eOMC 3852693\u003c\/li\u003e\n\u003cli\u003eVolvo Penta 3852693\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0347 valve stem seal set include?\u003c\/strong\u003e The Sierra 18-0347 set includes 8 valve stem seals, enough for a full single-engine replacement on the applicable 4 cyl. 3.7L Mercruiser 470 engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engine does part number 18-0347 fit?\u003c\/strong\u003e Sierra 18-0347 is built for the 4 cyl. 3.7L Mercruiser 470 engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0347 the same as Mercury Marine 27-52145?\u003c\/strong\u003e Yes, Sierra 18-0347 directly cross-references to Mercury Marine 27-52145, along with Mercury Marine 27-806452 and 27-34041, and installs as a direct replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes 18-0347 replace OMC valve stem seals?\u003c\/strong\u003e Yes, Sierra 18-0347 cross-references to OMC part numbers 913277, 912981, and 3852693.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this compatible with Volvo Penta engines?\u003c\/strong\u003e Sierra 18-0347 cross-references to Volvo Penta part number 3852693.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many seals come in the 18-0347 set?\u003c\/strong\u003e The set contains 8 valve stem seals, matching a full complement for the 4 cyl. 3.7L Mercruiser 470 engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0347 seal set weigh?\u003c\/strong\u003e The set weighs 0.19 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the symptoms of worn valve stem seals that 18-0347 addresses?\u003c\/strong\u003e Worn valve stem seals commonly cause blue exhaust smoke, fouled spark plugs, and gradual oil consumption; replacing them with the Sierra 18-0347 set restores proper oil control at the valve guides.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0347 an OEM part or an aftermarket replacement?\u003c\/strong\u003e Sierra 18-0347 is an aftermarket part manufactured to meet or exceed original equipment quality, cross-referenced to the Mercury Marine, OMC, and Volvo Penta OEM numbers it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes 18-0347 also cross-reference to GLM or Mallory part numbers?\u003c\/strong\u003e Yes, Sierra 18-0347 cross-references to GLM 32210 and Mallory 9-61317.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988068610267,"sku":"SIE-18-0347","price":93.34,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0347_lg__66533.1558118554.500.750.jpg?v=1785188407"},{"product_id":"sierra-18-0403-intake-manifold-gasket-kit-for-mercruiser-7-4l-454-502-mag-bravo-ii-mie-8-2l-1978-1997-replaces-27-805722a1","title":"Sierra 18-0403 Intake Gasket Kit, Replaces Mercury Marine 27-52571, Fits MCM 370\/400\/325\/454\/502 Mag \u0026 MIE 82L 1978-1997","description":"\u003cp\u003eThe Sierra 18-0403 Intake Gasket Kit is a complete gasket set engineered to seal the intake manifold on select Mercury Marine sterndrive and inboard engines. This kit is built as a direct equivalent to the original Mercury Marine intake gasket, giving boat owners and marine technicians a reliable way to restore a proper seal at the intake manifold without sourcing a discontinued or hard-to-find factory part.\u003c\/p\u003e\u003cp\u003eThe kit includes the full complement of gaskets needed for a complete intake gasket replacement in a single package, finished in white. It is designed for use on MCM 370, 400, 325, 454, and 502 Mag engines, as well as the 74L Bravo II and MIE 82L, covering the 1978-1997 production span for these applications. Installing a fresh intake gasket kit at this interval helps prevent coolant, oil, or intake air leaks caused by a hardened or degraded factory gasket.\u003c\/p\u003e\u003cp\u003eAt 0.61 pounds, the 18-0403 kit ships as a compact, ready-to-install package. Because it carries the Sierra 18-0403 part number and cross-references Mercury Marine 27-52571, it can be ordered with confidence as a fit-for-purpose replacement rather than a generic aftermarket substitute.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0403\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Intake Gasket Kit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Components:\u003c\/strong\u003e Intake Gasket Kit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.61 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282200602\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 27-52571\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMCM 370, 400, 325, 454, 502 Mag\u003c\/li\u003e\n\u003cli\u003e74L Bravo II\u003c\/li\u003e\n\u003cli\u003eMIE 82L\u003c\/li\u003e\n\u003cli\u003e1978-1997\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-52571\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0403 intake gasket kit fit?\u003c\/strong\u003e The 18-0403 kit fits MCM 370, 400, 325, 454, and 502 Mag engines, along with the 74L Bravo II and MIE 82L, covering the 1978-1997 model years for these applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does this gasket kit replace?\u003c\/strong\u003e This kit cross-references Mercury Marine OEM number 27-52571, so it can be ordered as a direct equivalent to that factory part under Sierra part number 18-0403.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0403 intake gasket kit weigh?\u003c\/strong\u003e It weighs 0.61 pounds as packaged.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0403 gasket kit?\u003c\/strong\u003e It is finished in white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a complete gasket set or a single gasket?\u003c\/strong\u003e The 18-0403 is a kit that includes the full set of intake gaskets needed for the job, not a single individual gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this kit work on any Mercury Marine engine?\u003c\/strong\u003e No, the 18-0403 is designed specifically for the MCM 370, 400, 325, 454, and 502 Mag engines and the 74L Bravo II and MIE 82L from 1978-1997; it is not a universal fit across all Mercury Marine engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0403 kit genuine Sierra or a generic aftermarket part?\u003c\/strong\u003e It is a genuine Sierra-branded part, sold under Sierra part number 18-0403, engineered as a cross-reference match to Mercury Marine 27-52571 rather than a generic substitute.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the intake gasket with this kit?\u003c\/strong\u003e An intake gasket kit like the 18-0403 should be installed any time the intake manifold is removed or when signs of a leaking intake seal, such as coolant or oil seepage at the manifold, are present.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0403 kit include everything needed for installation?\u003c\/strong\u003e Yes, the kit's included components consist of the intake gasket set required for the job, packaged together as the 18-0403.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0403 intake gasket kit?\u003c\/strong\u003e The UPC for this product is 808282200602.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 74L Bravo II use the same intake gasket kit as the MCM engines?\u003c\/strong\u003e Yes, the Sierra 18-0403 kit covers the 74L Bravo II in addition to the MCM 370, 400, 325, 454, 502 Mag, and MIE 82L engines.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988073591003,"sku":"SIE-18-0403","price":86.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0403_lg__25780.1558120638.500.750.jpg?v=1785188517"},{"product_id":"sierra-18-0411-oil-pan-gasket-set-for-mercruiser-gm-350-cid-5-7l-starboard-dipstick-replaces-27-90458a1","title":"Sierra 18-0411 Oil Pan Gasket Set, Replaces 27-90458A1 \u0026 27-90458, for Mercruiser GM 350 CID (5.7L) Starboard Dipstick Engines","description":"\u003cp\u003eThe Sierra 18-0411 Oil Pan Gasket Set is a replacement gasket kit engineered for Mercruiser GM 350 CID (5.7L) marine engines equipped with a starboard dipstick configuration. It is built to meet or exceed the quality of the original equipment gasket it replaces, providing a reliable seal between the oil pan and engine block to prevent oil leaks and maintain proper lubrication pressure. Each set is manufactured to precise tolerances so it seats correctly against factory mating surfaces without the need for excessive sealant buildup.\u003c\/p\u003e\u003cp\u003eThis gasket set is a direct cross-reference for several OEM and aftermarket part numbers, making it a straightforward swap when servicing or rebuilding a Mercruiser GM 350 CID (5.7L) engine with a starboard-side dipstick. It ships as a complete set so installers have the gaskets needed for the job in one package, reducing trips back to the parts counter mid-repair. Sierra part 18-0411 is sold under the UPC 030999873842 for easy identification and ordering.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0411\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Oil Pan Gasket Set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.3 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999873842\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1 set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 27-90458A1, 27-90458, FI5000178, FI5000183\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e Mercruiser GM 350 CID (5.7L), Starboard Dipstick\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercruiser GM 350 CID (5.7L) engines with starboard dipstick\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e27-90458A1\u003c\/li\u003e\n\u003cli\u003e27-90458\u003c\/li\u003e\n\u003cli\u003eFI5000178\u003c\/li\u003e\n\u003cli\u003eFI5000183\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engine does the Sierra 18-0411 Oil Pan Gasket Set fit?\u003c\/strong\u003e It fits Mercruiser GM 350 CID (5.7L) engines that use a starboard-side dipstick configuration.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does 18-0411 replace?\u003c\/strong\u003e Sierra 18-0411 cross-references to 27-90458A1, 27-90458, FI5000178, and FI5000183.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0411 gasket set an OEM part or an aftermarket replacement?\u003c\/strong\u003e It is an aftermarket gasket set manufactured by Sierra to meet or exceed the quality of the original equipment oil pan gasket it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0411 Oil Pan Gasket Set weigh?\u003c\/strong\u003e The Sierra 18-0411 Oil Pan Gasket Set weighs 0.3 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-0411 gasket material?\u003c\/strong\u003e The gasket set is white in color.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets are included in the 18-0411 set?\u003c\/strong\u003e The Sierra 18-0411 Oil Pan Gasket Set is packaged as one complete set (1 unit) covering the oil pan sealing job.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill 18-0411 work on a Mercruiser engine with a port-side dipstick?\u003c\/strong\u003e Sierra 18-0411 is designated for the GM 350 CID (5.7L) engine configuration with a starboard dipstick; a port-dipstick engine should be matched against fitment before ordering, since these are distinct dipstick configurations.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0411 gasket set?\u003c\/strong\u003e The UPC for the Sierra 18-0411 Oil Pan Gasket Set is 030999873842.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0411 gasket set require additional sealant during installation?\u003c\/strong\u003e The Sierra 18-0411 Oil Pan Gasket Set is manufactured to seal properly against factory mating surfaces without needing excessive sealant buildup.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0411 the correct part number to order for this gasket set?\u003c\/strong\u003e Yes, 18-0411 is the Sierra part number for this oil pan gasket set, and it is the number to reference when ordering.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988073623771,"sku":"SIE-18-0411","price":35.32,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0411_lg__96798.1558120955.500.750.jpg?v=1785188038"},{"product_id":"sierra-18-0486-oil-strainer-seal-for-yamaha-outboard-gearcase-mpn-118-0486","title":"Sierra Oil Strainer Seal 18-0486 for Yamaha Outboard Gearcase \u0026 Drive","description":"\u003cp\u003eThe Sierra Oil Strainer Seal, part number 18-0486, is a replacement seal designed for Yamaha outboard gearcase and drive applications. It seals the oil strainer to prevent lubricant leaks and contamination from entering the gearcase, helping protect internal gear and bearing surfaces from water intrusion and debris. Keeping this seal in good condition is important whenever the oil strainer or gearcase is serviced, since a worn or damaged seal can allow gear lube to leak out or allow water to seep in, leading to premature wear of gearcase components. This is a small, low-cost part that is easy to overlook during a gearcase service, but it plays a direct role in keeping the lubrication system sealed and functioning correctly. It ships as a compact, lightweight seal sized to fit directly in place of the original equipment part, making it a straightforward swap during routine maintenance or a gearcase rebuild. Sierra is a widely recognized name in marine replacement parts, and this seal is manufactured to work as a direct fit for the Yamaha outboard gearcase and drive systems it is designed for.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0486\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Oil Strainer Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Yamaha Outboard Gearcase \u0026amp; Drive Parts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 4 x 4 x 0.5 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282385798\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eYamaha outboard gearcase and drive applications\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0486 oil strainer seal used for?\u003c\/strong\u003e It seals the oil strainer in Yamaha outboard gearcase and drive applications, preventing gear lube leaks and keeping water and debris out of the gearcase.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this seal fit Yamaha outboards specifically?\u003c\/strong\u003e Yes, Sierra part 18-0486 is designed for Yamaha outboard gearcase and drive applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the package dimensions of the 18-0486 oil strainer seal?\u003c\/strong\u003e The Sierra 18-0486 oil strainer seal has package dimensions of 4 x 4 x 0.5 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the oil strainer seal weigh?\u003c\/strong\u003e The Sierra 18-0486 oil strainer seal weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0486 a genuine Sierra part or aftermarket?\u003c\/strong\u003e It is a Sierra-branded replacement part, sold under Sierra's own part number 18-0486 rather than an OEM Yamaha number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the oil strainer seal on my Yamaha outboard?\u003c\/strong\u003e Replace Sierra part 18-0486 any time the oil strainer is removed for gearcase service, or if it shows signs of wear, cracking, or leaking gear lube.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if a worn oil strainer seal is not replaced?\u003c\/strong\u003e A worn 18-0486 seal can allow gear lubricant to leak out or let water intrude into the gearcase, which can lead to premature wear of internal gearcase components.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order this part?\u003c\/strong\u003e Ordering Sierra 18-0486 gets you the single oil strainer seal component for the gearcase oil strainer.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0486 seal easy to install myself?\u003c\/strong\u003e Yes, it is a simple seal that fits in place of the original oil strainer seal during routine gearcase maintenance or a rebuild.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the Sierra 18-0486 seal made from?\u003c\/strong\u003e Material details for the Sierra 18-0486 oil strainer seal are not specified by the manufacturer.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988075163867,"sku":"SIE-18-0486","price":7.12,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0486__85483.1739477160.500.750.jpg?v=1785189080"},{"product_id":"intake-manifold-gasket-set-27-8243261-for-mercruiser-4-3l-262-mag-gen-ii-1996-up-sierra-18-0487","title":"Sierra 18-0487 Intake Manifold Gasket for Mercury 4.3L and MCM 262 Mag Engines, Replaces 27-8243261","description":"\u003cp\u003eThe Sierra 18-0487 is an intake manifold gasket built to seal the connection between the intake manifold and cylinder heads on select Mercury marine engines, preventing air, fuel, and coolant leaks at that joint. It is a direct replacement for Mercury gasket 27-8243261, giving boat owners and technicians a way to source the correct seal without going through Mercury directly. The gasket is engineered to match the original fit for the MCM 262 Mag and 4.3L\/LX\/LH\/LXH (Gen+) engine family, 1996 and later, so it lines up with the factory mounting points and sealing surfaces without modification.\u003c\/p\u003e\u003cp\u003eEach package contains one gasket (Sierra part number 18-0487), identified by UPC 808282187248. As a wear item, the intake manifold gasket is typically replaced whenever the intake manifold is removed for service, or when a leak develops at the intake-to-head joint. Installing the correct gasket helps maintain proper sealing and engine performance on the engines it is designed for.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0487\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Intake Manifold Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282187248\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Items:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.35 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplaces (OEM):\u003c\/strong\u003e 27-8243261\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMCM 262 Mag and 4.3L\/LX\/LH\/LXH (Gen+) engines, 1996 and later\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-8243261\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0487 intake manifold gasket fit?\u003c\/strong\u003e The Sierra 18-0487 fits the MCM 262 Mag and 4.3L\/LX\/LH\/LXH (Gen+) Mercury engine family, 1996 and later.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0487 a cross-reference for Mercury gasket 27-8243261?\u003c\/strong\u003e Yes, the 18-0487 is a direct replacement for Mercury intake manifold gasket 27-8243261.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets are included with the Sierra 18-0487?\u003c\/strong\u003e One intake manifold gasket is included per package of the Sierra 18-0487.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0487 gasket weigh?\u003c\/strong\u003e The Sierra 18-0487 intake manifold gasket weighs 0.35 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0487 intake manifold gasket?\u003c\/strong\u003e The UPC for the Sierra 18-0487 is 808282187248.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0487 fit 4.3L LX and LH engine variants?\u003c\/strong\u003e Yes, the 18-0487 is designed for the 4.3L\/LX\/LH\/LXH (Gen+) engines in addition to the MCM 262 Mag.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen would I need to replace this intake manifold gasket?\u003c\/strong\u003e Replacement of the 18-0487 is typically needed when the intake manifold is removed for service or when a leak develops at the intake-to-head sealing surface on a fitted MCM 262 Mag or 4.3L\/LX\/LH\/LXH (Gen+) engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat Sierra part number should I order for this Mercury gasket?\u003c\/strong\u003e Order Sierra part number 18-0487, which replaces Mercury gasket 27-8243261.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0487 an OEM Mercury part or an aftermarket equivalent?\u003c\/strong\u003e The 18-0487 is a Sierra-brand gasket manufactured as a replacement for Mercury gasket 27-8243261, not an OEM Mercury part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat model year range does the 18-0487 gasket cover?\u003c\/strong\u003e The 18-0487 is listed for MCM 262 Mag and 4.3L\/LX\/LH\/LXH (Gen+) engines built in 1996 or later.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988075294939,"sku":"SIE-18-0487","price":85.78,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0487_lg__64552.1558121261.500.750.jpg?v=1785188467"},{"product_id":"sierra-18-0488-intake-manifold-gasket-set-replaces-mercury-27-807473a1-fits-mercruiser-350-mag-5-0l-5-7l-lx-gen-ii-1996-up","title":"Sierra 18-0488 Intake Gasket, Replaces Mercury Marine 27-807473A1","description":"\u003cp\u003eThe Sierra 18-0488 is a white intake gasket engineered as a direct equivalent for Mercury Marine engines that call for OEM number 27-807473A1. It seats between the intake manifold and engine block to seal against exhaust gas and coolant leakage at the intake mating surface, a common failure point as factory gaskets age and lose compression. The gasket is round in shape and manufactured to OEM specifications for fit and sealing performance, making it a straightforward like-for-like replacement during a manifold gasket job or general engine maintenance. At 0.33 pounds, it ships as a single-count gasket ready to install without modification. Because it is built to OEM dimensions and material specification, it installs the same way the original Mercury Marine gasket does, using the same fastener pattern and sealing surface, so no special tools or adapters are required beyond a standard gasket replacement procedure.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0488\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Intake Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e Taiwan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.33 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282187255\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for Mercury Marine engines originally fitted with intake gasket 27-807473A1.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-807473A1\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0488 intake gasket fit?\u003c\/strong\u003e The Sierra 18-0488 is built as a direct equivalent for Mercury Marine intake applications that originally used OEM gasket 27-807473A1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0488 the same as Mercury Marine 27-807473A1?\u003c\/strong\u003e Yes, part number 18-0488 is manufactured to replace Mercury Marine OEM gasket 27-807473A1 directly, matching its fit and sealing function.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is this gasket?\u003c\/strong\u003e The 18-0488 intake gasket is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape is the Sierra 18-0488 gasket?\u003c\/strong\u003e It is round in shape, matching the sealing surface it is designed to cover.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0488 intake gasket weigh?\u003c\/strong\u003e This gasket weighs 0.33 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the Sierra 18-0488 gasket manufactured?\u003c\/strong\u003e The country of origin for the 18-0488 intake gasket is Taiwan.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Mercury Marine part or an aftermarket replacement?\u003c\/strong\u003e The 18-0488 is a Sierra-branded aftermarket gasket engineered to OEM specifications as a replacement for Mercury Marine 27-807473A1, not a genuine Mercury Marine part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in the package?\u003c\/strong\u003e The Sierra 18-0488 is sold as a single gasket, one unit per package.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I install the 18-0488 gasket myself?\u003c\/strong\u003e Yes, since it matches the OEM fit and dimensions of 27-807473A1, it installs the same way as the original Mercury Marine gasket during a standard intake manifold service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0488 intake gasket?\u003c\/strong\u003e The UPC for the 18-0488 intake gasket is 808282187255.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988075360475,"sku":"SIE-18-0488","price":50.55,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0488_lg__65705.1558121335.500.750.jpg?v=1785187970"},{"product_id":"sierra-18-0515-oil-seal-replaces-mercury-36-30530-fits-mercury-4-hp-40-outboard-powerhead-crankshaft","title":"Sierra 18-0515 Oil Seal, Replaces Mercury 26-30530, for Outboard Powerhead Crankshaft","description":"\u003cp\u003eThe Sierra 18-0515 is a round oil seal designed for Mercury outboard powerhead crankshaft applications. It seals the crankshaft bore to keep lubricating oil contained within the powerhead while preventing water and contaminants from entering, protecting internal engine components from leaks and premature wear. The seal is finished in white and is built to Sierra's standard fit and function for this position.\u003c\/p\u003e\u003cp\u003eThis seal carries precise dimensions of 0.540 inch shaft size, 1.004 inch outside diameter, and 0.303 inch width, matching the profile of the Mercury OEM oil seal it replaces. Because oil seals in this size range are used across multiple engine positions, always confirm these three measurements against your old seal or your engine's parts diagram before ordering to ensure a correct fit.\u003c\/p\u003e\u003cp\u003eSierra International supplies replacement parts for marine engines, and the 18-0515 is cataloged specifically as a Mercury outboard powerhead crankshaft seal, making it a straightforward like-for-like replacement for the corresponding Mercury OEM part. It is sold as a single seal.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0515\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-30530\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.540 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 1.004 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.303 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874276\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Mercury outboard powerhead crankshaft seal\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for Mercury outboard powerhead crankshaft applications requiring an oil seal with a 0.540 inch shaft size, 1.004 inch outside diameter, and 0.303 inch width. Verify these dimensions against your existing seal before purchase.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-30530\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0515 oil seal fit?\u003c\/strong\u003e The Sierra 18-0515 is cataloged for Mercury outboard powerhead crankshaft applications, sealing the crankshaft bore to retain lubricating oil and keep out contaminants.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0515 the same as Mercury 26-30530?\u003c\/strong\u003e Yes, the 18-0515 is Sierra's direct replacement for Mercury OEM oil seal 26-30530, matching its shaft size, outside diameter, and width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0515 oil seal?\u003c\/strong\u003e This seal measures 0.540 inches at the shaft, 1.004 inches on the outside diameter, and 0.303 inches wide.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0515 oil seal?\u003c\/strong\u003e It is white, as manufactured by Sierra International.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0515 oil seal weigh?\u003c\/strong\u003e The Sierra 18-0515 weighs 0.01 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if this seal will fit my engine?\u003c\/strong\u003e Compare the shaft size, outside diameter, and width of your existing seal to the 18-0515 specs of 0.540 inches, 1.004 inches, and 0.303 inches respectively, since seals in this size range can be used in more than one engine position.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0515 a genuine Mercury part or aftermarket?\u003c\/strong\u003e The 18-0515 is a Sierra-manufactured aftermarket seal built to replace Mercury OEM part 26-30530, not a genuine Mercury-branded component.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape is the 18-0515 seal?\u003c\/strong\u003e The Sierra 18-0515 oil seal is round in shape.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat comes in the package with the 18-0515?\u003c\/strong\u003e The package includes one Sierra 18-0515 oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0515 oil seal?\u003c\/strong\u003e The UPC for this Sierra oil seal is 030999874276.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of part is the 18-0515?\u003c\/strong\u003e The 18-0515 is classified as a Mercury outboard powerhead crankshaft seal.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988075524315,"sku":"SIE-18-0515","price":9.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0515_lg__79364.1558118539.500.750.jpg?v=1785188113"},{"product_id":"sierra-18-0525-oil-seal-for-mercury-mercruiser-26-45587-0-390-in-shaft-marine-engine-seal","title":"Sierra Oil Seal 18-0525, Replaces 26-45587, 0.390 x 0.628 x 0.124 Inch","description":"\u003cp\u003eThe Sierra 18-0525 is a precision oil seal sized for a 0.390 inch shaft, with a 0.628 inch outside diameter and a 0.124 inch width. It is a direct replacement for OEM number 26-45587 and features a machined exterior finish for a consistent, leak-resistant fit at the shaft bore.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0525\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-45587\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.390 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 0.628 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.124 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874368\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned as a dimensional and functional match for applications originally fitted with OEM part 26-45587. Confirm your existing seal or housing calls for 26-45587 before ordering.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-45587\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part does the Sierra 18-0525 replace?\u003c\/strong\u003e It is a direct replacement for OEM number 26-45587, so any application calling for that part number accepts the Sierra 18-0525 oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the shaft size for this seal?\u003c\/strong\u003e 0.390 inches is the shaft size for the Sierra 18-0525 oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the outside diameter and width of the 18-0525 seal?\u003c\/strong\u003e The Sierra 18-0525 has a 0.628 inch outside diameter and a 0.124 inch width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0525 oil seal weigh?\u003c\/strong\u003e It weighs 0.01 pounds, consistent with its small, compact seal size.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0525 seal genuine Sierra or aftermarket?\u003c\/strong\u003e Yes, the 18-0525 is a genuine Sierra-branded part, manufactured as a direct-fit equivalent to OEM 26-45587.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat finish does the Sierra 18-0525 have?\u003c\/strong\u003e It has a machined exterior finish for consistent, accurate sealing at the shaft bore.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the 18-0525 in place of 26-45587 without modification?\u003c\/strong\u003e Yes, the Sierra 18-0525 is dimensionally matched to OEM 26-45587 and installs as a direct swap.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-0525?\u003c\/strong\u003e You receive one Sierra 18-0525 oil seal sized to 0.390 inch shaft, 0.628 inch OD, and 0.124 inch width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the part number 18-0525 identify the shaft size or the OEM equivalent?\u003c\/strong\u003e 18-0525 is the Sierra part number itself; 26-45587 is the OEM number it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this seal suitable for both port and starboard applications?\u003c\/strong\u003e No side-specific designation is given for the 18-0525; it is a standard oil seal sized by shaft diameter, OD, and width rather than by mounting side.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988075589851,"sku":"SIE-18-0525","price":7.41,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0525_lg__12658.1558118991.500.750.jpg?v=1785188326"},{"product_id":"oil-seal-26-48443-for-mercruiser-stern-drive-sierra-18-0526-0-750-id-x-1-379-od-x-0-256","title":"Sierra Oil Seal 18-0526 - OEM 26-48443 for Mercruiser Stern Drive, 0.750 Inch Shaft","description":"\u003cp\u003eThe Sierra 18-0526 is an oil seal engineered for Mercruiser stern drive applications, replacing OEM number 26-48443. It is built to contain gear lubricant and keep water and contaminants out of the drive housing, protecting internal gears and bearings from premature wear. The seal measures 0.750 inches at the shaft, 1.379 inches on the outer diameter, and 0.256 inches in width, and is finished in black. Sierra constructs this seal using quality materials selected for exceptional life and performance in the marine environment, where seals are constantly exposed to water, salt, and lubricant. Each unit ships as a single oil seal, ready to install as a direct replacement during drive service or seal maintenance. Because stern drive seals are a wear item that hardens and loses sealing ability over time, replacing the 18-0526 at the proper interval helps prevent lubricant leaks and water intrusion that can lead to more costly drive repairs.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0526\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.750 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.379 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.256 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Black\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 oil seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874375\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercruiser stern drive\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-48443\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0526 oil seal replace?\u003c\/strong\u003e It is a direct replacement for OEM number 26-48443 used on Mercruiser stern drive units.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shaft size is the 18-0526 seal designed for?\u003c\/strong\u003e This seal has a 0.750 inch shaft size, with a 1.379 inch outer diameter and a 0.256 inch width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0526 oil seal?\u003c\/strong\u003e It is finished in black.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0526 oil seal weigh?\u003c\/strong\u003e The seal weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many seals come in one order?\u003c\/strong\u003e One order includes a single 18-0526 oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-0526 oil seal used for?\u003c\/strong\u003e It seals the Mercruiser stern drive housing, keeping gear lubricant in and water and debris out.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0526 an OEM or aftermarket part?\u003c\/strong\u003e It is an aftermarket Sierra part manufactured as a replacement for OEM number 26-48443, not an OEM Mercruiser part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should a stern drive oil seal like the 18-0526 be replaced?\u003c\/strong\u003e A seal in this position should be replaced when it hardens, leaks lubricant, or allows water intrusion into the drive housing, or as part of routine drive service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat UPC is associated with the Sierra 18-0526 oil seal?\u003c\/strong\u003e The UPC for this oil seal is 030999874375.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0526 seal come with installation hardware?\u003c\/strong\u003e No, the package includes only the oil seal itself; no additional hardware is included.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988077031643,"sku":"SIE-18-0526","price":14.85,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0526_lg__95684.1558119055.500.750.jpg?v=1785188305"},{"product_id":"sierra-18-0539-exhaust-leg-rubber-seal-gasket-for-mercury-outboards-replaces-mercury-37721-37721001-glm-85630","title":"Sierra 18-0539 Rubber Seal Gasket - Replaces Mercury 37721","description":"\u003cp\u003eThe Sierra 18-0539 Rubber Seal Gasket is a rubber exhaust leg seal used in Mercury outboard cooling systems. It is designed as a direct replacement for the original equipment seal, restoring a tight, leak-free connection where the exhaust leg meets the powerhead cooling passages. A worn or hardened rubber seal in this location can allow water or exhaust gases to escape past the joint, so replacing it with a properly sized gasket like the 18-0539 helps maintain correct sealing pressure and cooling system integrity.\u003c\/p\u003e\u003cp\u003eMade of rubber, this seal is compact and precisely sized to fit its intended mounting location, with dimensions of 0.39 x 0.39 x 0.39 inches and a weight of 0.07 pounds. It is built to meet or exceed the quality of the original equipment part it replaces, making it a reliable choice for routine maintenance or repair of the exhaust cooling seal. This is a small, low-cost component, but correct fitment matters since it is engineered as a like-for-like replacement for Mercury 37721.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0539\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Rubber Seal Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Rubber\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874474\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury 37721\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0539 used for?\u003c\/strong\u003e The Sierra 18-0539 is a rubber seal gasket used in the exhaust leg area of Mercury outboard cooling systems, sealing the joint to prevent water or exhaust leaks.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0539 a direct replacement for Mercury 37721?\u003c\/strong\u003e Yes, the 18-0539 is manufactured as a direct replacement for Mercury part 37721.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0539 seal made from?\u003c\/strong\u003e It is made of rubber, which allows it to compress and form a tight seal against mating surfaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0539 gasket weigh?\u003c\/strong\u003e This gasket weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0539 rubber seal?\u003c\/strong\u003e The seal measures 0.39 x 0.39 x 0.39 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0539 meet OEM quality standards?\u003c\/strong\u003e Sierra manufactures the 18-0539 to meet or exceed the quality of the original equipment Mercury 37721 seal it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0539 gasket?\u003c\/strong\u003e The UPC for the Sierra 18-0539 Rubber Seal Gasket is 030999874474.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0539 only for Mercury outboards?\u003c\/strong\u003e The 18-0539 is designed to replace the Mercury 37721 seal used in Mercury outboard cooling systems.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat comes in the package with the 18-0539?\u003c\/strong\u003e The Sierra 18-0539 is sold as a single rubber seal gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace this rubber seal?\u003c\/strong\u003e Over time the rubber in an exhaust leg seal like the 18-0539 can harden or crack, allowing leaks; replacing it with a new Sierra 18-0539 restores a proper seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the Sierra 18-0539 be reused after removal?\u003c\/strong\u003e No, once a rubber seal gasket like the 18-0539 is compressed and removed it typically loses its sealing ability and should be replaced with a new one.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988077064411,"sku":"SIE-18-0539","price":8.35,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0539_lg__42314.1558119442.500.750.jpg?v=1785189148"},{"product_id":"sierra-18-0549-plug-off-cap-replaces-omc-909829-1-in-i-d-fits-v-8-stern-drives-inboards-1977-present","title":"Sierra 18-0549 Plug Off Cap, 1 Inch I.D., Replaces OMC 909829, V-8 Stern Drives and Inboards 1977 to Present","description":"\u003cp\u003eThe Sierra 18-0549 Plug Off Cap is a machined marine plug designed to seal a 1 inch inside-diameter opening on qualifying V-8 model stern drives and inboards built from 1977 to present. It is a direct replacement for OMC part number 909829, making it a straightforward swap when the original plug is damaged, corroded, or missing during service and inspection work. The cap is a simple, single-piece component with no moving parts, built to hold a reliable seal against water and fluid intrusion at its mounting location. Its compact size and light weight of 0.05 pounds make it an easy, low-cost item to keep on hand as a spare for routine maintenance. Buyers working on qualifying V-8 stern drive and inboard applications should confirm the 1 inch I.D. Opening size before ordering, since Sierra also offers the 18-0550 Plug Off Cap with a larger 1 1\/4 inch I.D. For the same application range but a different opening size. The 18-0549 carries UPC 030999874535 for easy identification when ordering or verifying stock.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0549\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInside Diameter:\u003c\/strong\u003e 1 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 4 x 1 x 5 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.05 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874535\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e V-8 Model Stern Drives and Inboards (1977 to present)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplaces:\u003c\/strong\u003e OMC 909829\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eV-8 Model Stern Drives and Inboards (1977 to present)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eOMC 909829\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0549 Plug Off Cap?\u003c\/strong\u003e It is a machined plug off cap made by Sierra, part number 18-0549, used to seal a 1 inch inside-diameter opening on qualifying V-8 model stern drives and inboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the inside diameter of the 18-0549 plug off cap?\u003c\/strong\u003e The 18-0549 has a 1 inch inside diameter (I.D.).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engines and drives does the Sierra 18-0549 fit?\u003c\/strong\u003e This cap fits V-8 model stern drives and inboards built from 1977 to present.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0549 replace OMC part number 909829?\u003c\/strong\u003e Yes, the 18-0549 is a direct replacement for OMC 909829.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the difference between the Sierra 18-0549 and Sierra 18-0550?\u003c\/strong\u003e The 18-0549 has a 1 inch I.D. And replaces OMC 909829, while the 18-0550 has a larger 1 1\/4 inch I.D. And replaces OMC 909830; both cover V-8 model stern drives and inboards from 1977 to present but are separate part numbers, so the correct one depends on the opening size on your unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0549 plug off cap weigh?\u003c\/strong\u003e It weighs 0.05 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0549 a genuine Sierra part?\u003c\/strong\u003e Yes, the 18-0549 is manufactured under the Sierra brand and is not discontinued.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0549 plug off cap?\u003c\/strong\u003e The UPC for this Sierra plug off cap is 030999874535.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the Sierra 18-0549 fit a 1 1\/4 inch opening?\u003c\/strong\u003e No, the 18-0549 is sized for a 1 inch I.D. Opening; a 1 1\/4 inch opening requires the Sierra 18-0550 instead.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat years of V-8 stern drives and inboards does the 18-0549 cover?\u003c\/strong\u003e The 18-0549 plug off cap covers V-8 model stern drives and inboards from 1977 to present.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988077261019,"sku":"SIE-18-0549","price":11.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0549_lg__47603.1558119978.500.750.jpg?v=1785188055"},{"product_id":"sierra-18-0550-plug-off-cap-1-1-4-in-31-8mm-replaces-omc-909830-evinrude-johnson-3852476","title":"Sierra 18-0550 Plug Off Cap, Replaces OMC 909830, 1-1\/4 Inch","description":"\u003cp\u003eThe Sierra 18-0550 Plug Off Cap is a plastic plug cap used to seal an unused port on marine exhaust manifold applications. It is sized for a 1-1\/4 inch (31.8mm) opening and is molded in white plastic for durability in the marine engine compartment environment. This cap is designed as a direct aftermarket equivalent to OMC 909830, meeting or exceeding the performance of the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003eThe 18-0550 is a simple, purpose-built component: a single plug that presses or threads into place to close off an exhaust manifold port that is not being used in a given engine configuration, keeping the cooling and exhaust system sealed properly. Because it is interchangeable with several OEM and aftermarket cross-reference numbers, it can be used to service a range of OMC, Evinrude\/Johnson, GLM, and Mallory-numbered applications that call for this same 1-1\/4 inch plug cap. Each unit ships as a single cap ready to install.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0550\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Plug Off Cap\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Plastic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInside Diameter:\u003c\/strong\u003e 1-1\/4 inch (31.8mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.08 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 plug off cap per unit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e GLM 22280, Evinrude\/Johnson 909830, 3852476, Mallory 9-42721, OMC 909830\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits applications calling for a 1-1\/4 inch (31.8mm) exhaust manifold plug off cap, including those originally equipped with OMC 909830 or 3852476.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 22280\u003c\/li\u003e\n\u003cli\u003eEvinrude\/Johnson 909830\u003c\/li\u003e\n\u003cli\u003e3852476\u003c\/li\u003e\n\u003cli\u003eMallory 9-42721\u003c\/li\u003e\n\u003cli\u003eOMC 909830\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0550 Plug Off Cap used for?\u003c\/strong\u003e The Sierra 18-0550 is a plastic plug cap that seals an unused 1-1\/4 inch exhaust manifold port on applicable marine engines, keeping the exhaust and cooling passages closed off where a fitting is not installed.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size is the Sierra 18-0550 plug off cap?\u003c\/strong\u003e It has a 1-1\/4 inch (31.8mm) inside diameter, sized to fit the port opening it is designed to seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0550 replace OMC 909830?\u003c\/strong\u003e Yes, the Sierra 18-0550 is interchangeable with OMC 909830 and is built to meet or exceed the performance of that original equipment part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat other part numbers cross-reference to the Sierra 18-0550?\u003c\/strong\u003e The 18-0550 is interchangeable with GLM 22280, Evinrude\/Johnson 909830, Evinrude\/Johnson 3852476, Mallory 9-42721, and OMC 909830 and 3852476.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the Sierra 18-0550 plug off cap made from?\u003c\/strong\u003e It is made of white plastic, a lightweight material suited to sealing exhaust manifold ports in the marine engine compartment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0550 genuine OEM or aftermarket?\u003c\/strong\u003e It is a Sierra aftermarket part manufactured to meet or exceed the specifications of the original equipment part it replaces, such as OMC 909830.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many plug off caps come in one Sierra 18-0550 package?\u003c\/strong\u003e One Sierra 18-0550 plug off cap is included per unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0550 plug off cap weigh?\u003c\/strong\u003e The 18-0550 weighs 0.08 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-0550 be used in place of a Mallory 9-42721 cap?\u003c\/strong\u003e Yes, the Mallory 9-42721 is one of the cross-reference numbers the Sierra 18-0550 is interchangeable with.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0550 threaded or a press-fit plug?\u003c\/strong\u003e The 18-0550 is a plug off cap sized to a 1-1\/4 inch (31.8mm) opening; specific thread or press-fit installation details beyond that sizing are not specified.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078506203,"sku":"SIE-18-0550","price":10.66,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/Untitled-1__72359.1771572386.500.750.jpg?v=1785188038"},{"product_id":"sierra-18-0558-oil-seal-for-volvo-penta-aq200-aq290-replaces-oem-851407-44-x-58-33-x-7-mm","title":"Sierra Seal 18-0558, 44mm ID x 7mm Width Marine Shaft Seal","description":"\u003cp\u003eThe Sierra 18-0558 is a marine oil seal built to keep water and contaminants out while retaining lubrication in rotating shaft applications on inboard and sterndrive engines. It is engineered to meet the demands of high-horsepower marine engines and to hold up in the harsh marine environment, where constant exposure to saltwater, vibration, and heat cycling causes ordinary seals to fail prematurely. Sierra states that this seal meets or exceeds the performance of the original equipment part it replaces, making it a dependable choice when a shaft seal needs replacing during an engine rebuild, lower-unit service, or routine maintenance.\u003c\/p\u003e\u003cp\u003eThe seal has a machined exterior finish for a precise, consistent fit against its mating bore, and it is sized with a 44 mm inside diameter and a 7 mm width. Its compact size and light weight make it easy to install as part of a broader engine or drive service without adding measurable bulk to the assembly. Sierra supplies parts like this one to OEM engine manufacturers and boat builders, so the 18-0558 is manufactured to the same quality standard used in original production.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0558\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInside Diameter:\u003c\/strong\u003e 44 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 7 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.04 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282265427\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the Sierra 18-0558 seal?\u003c\/strong\u003e The Sierra 18-0558 seal has a 44 mm inside diameter and a 7 mm width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0558 seal weigh?\u003c\/strong\u003e It weighs 0.04 pounds, a lightweight component sized for shaft seal applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0558 an OEM-equivalent part?\u003c\/strong\u003e Yes, Sierra states this seal meets or exceeds the performance of the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat finish does the 18-0558 seal have?\u003c\/strong\u003e A machined exterior finish is used on the Sierra 18-0558 to ensure a precise, consistent fit in its mating bore.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order part number 18-0558?\u003c\/strong\u003e The order includes one Sierra 18-0558 seal; no additional hardware or gaskets are bundled with it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-0558 seal be used in marine engine or drive service?\u003c\/strong\u003e Yes, it is designed for use as a shaft seal in marine engine and drive applications where water and contaminant exclusion is required.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes Sierra manufacture the 18-0558 to OEM standards?\u003c\/strong\u003e Sierra supplies parts to OEM engine manufacturers and boat builders, and the 18-0558 seal is produced to that same quality standard.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0558 seal still in production?\u003c\/strong\u003e Yes, the Sierra 18-0558 seal is an active, currently produced part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is the 18-0558 different from a generic aftermarket seal?\u003c\/strong\u003e The 18-0558 is manufactured by Sierra to meet or exceed the original equipment part's specifications, rather than being a generic universal-fit substitute.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the inside diameter of the 18-0558 shaft seal?\u003c\/strong\u003e The inside diameter of the Sierra 18-0558 is 44 mm, sized to seat around the shaft it seals.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078604507,"sku":"SIE-18-0558","price":19.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-0558__94667.1722518353.500.750.jpg?v=1785188012"},{"product_id":"sierra-18-0559-marine-oil-seal-replaces-omc-332585-evinrude-johnson-outboard-prop-driveshaft-seal-0-285-id-x-0-357-od-x-0-940","title":"Sierra 18-0559 Outboard Prop Shaft Oil Seal, Replaces OMC 332585","description":"\u003cp\u003eThe Sierra 18-0559 is an oil seal built for outboard prop shaft and driveshaft applications. It keeps water out and lubricant in around the rotating shaft, protecting the lower unit gearcase from water intrusion and preventing lubricant loss that can lead to premature gear and bearing wear. The seal is sized to a 0.357 inch outside diameter, a 0.285 inch shaft size, and a 0.940 inch width, so it seats precisely in the housing bore it is designed for and rides correctly against the shaft without leaking.\u003c\/p\u003e\u003cp\u003eThis part is a direct equivalent to OEM OMC 332585, giving boat owners and marine technicians a way to source the correct seal without going through OMC directly. It is a small, precise component, so correct orientation and a light coat of marine grease during installation help it seat fully and seal properly on the first try. Because it is a wear item exposed to constant water contact and shaft rotation, it is a common preventive-maintenance replacement during lower unit service, gearcase rebuilds, or whenever water is found in the gear lubricant.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0559\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 0.357 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.285 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.940 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874603\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e OMC 332585\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for outboard prop shaft and driveshaft seal applications.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eOMC 332585\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0559 oil seal replace?\u003c\/strong\u003e The Sierra 18-0559 is a direct cross reference to OEM OMC 332585, so it installs as a like-for-like replacement for that part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size is the Sierra 18-0559 oil seal?\u003c\/strong\u003e It measures 0.357 inches outside diameter, 0.285 inches shaft size, and 0.940 inches in width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0559 an OEM part or an aftermarket equivalent?\u003c\/strong\u003e It is a Sierra-branded aftermarket seal manufactured as a direct equivalent to OEM OMC 332585, not an OMC-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat application is the 18-0559 seal used for?\u003c\/strong\u003e This oil seal is designed for outboard prop shaft and driveshaft sealing, keeping water out of the gearcase and lubricant in around the rotating shaft.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0559 oil seal weigh?\u003c\/strong\u003e The seal weighs 0.01 pounds, consistent with its small, precise seal profile.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when you order the 18-0559?\u003c\/strong\u003e Ordering the Sierra 18-0559 gets you a single oil seal sized to a 0.357 inch O.D., 0.285 inch shaft size, and 0.940 inch width; no gaskets or hardware are included.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace this seal?\u003c\/strong\u003e If water shows up in the gearcase lubricant or the lower unit is being rebuilt, the prop shaft seal is a common wear item to replace, and the 18-0559 is sized for that job.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0559 come with an OEM number I can cross-reference?\u003c\/strong\u003e Yes, its OEM cross reference is OMC 332585, which can be used to confirm it is the correct seal for your application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is the Sierra 18-0559 installed?\u003c\/strong\u003e The seal should be pressed squarely into its housing bore with the correct orientation and a light coat of marine grease on the lip to help it seat fully against the 0.285 inch shaft without leaking.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0559 oil seal?\u003c\/strong\u003e The UPC for this Sierra oil seal, part number 18-0559, is 030999874603.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078735579,"sku":"SIE-18-0559","price":2.13,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0559_lg__33351.1558120404.500.750.jpg?v=1785188937"},{"product_id":"sierra-18-0564-oil-seal-for-mercury-outboard-powerhead-replaces-mercury-26-888483-1-250-id-x-1-690-od-x-0-256","title":"Sierra 18-0564 Oil Seal, White, Replaces Mercury Marine 26-888483","description":"\u003cp\u003eThe Sierra 18-0564 Oil Seal is a machined, white-finish seal designed for outboard powerhead applications where a reliable, leak-resistant seal is needed around a rotating shaft. Its compact size, measuring 0.39 x 0.39 x 0.39 inches, makes it suited for tight clearances found in outboard powerhead assemblies. The seal is built with a machined exterior for a consistent, precise fit, helping maintain proper sealing pressure and reduce the risk of oil or lubricant leakage during operation.\u003c\/p\u003e\u003cp\u003eThis oil seal is a universal-fit component, meaning it is not restricted to a single engine family, and it directly replaces Mercury Marine part number 26-888483, making it a straightforward swap for boat owners and technicians performing powerhead seal maintenance. At just 0.01 pounds, it is a lightweight, small-parts item that is easy to keep on hand for routine service work or as a spare when servicing Mercury outboard powerheads.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0564\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Oil Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFit Type:\u003c\/strong\u003e Universal Fit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282200275\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e Mercury Marine 26-888483\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eThis oil seal is a universal-fit part and is not limited to a specific engine model or year range.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury Marine 26-888483\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0564 oil seal used for?\u003c\/strong\u003e The Sierra 18-0564 is an oil seal designed to prevent lubricant leakage around a rotating shaft in an outboard powerhead, helping maintain proper internal sealing during engine operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0564 oil seal replace an OEM Mercury part?\u003c\/strong\u003e Yes, the Sierra 18-0564 oil seal directly replaces Mercury Marine part number 26-888483.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0564 oil seal?\u003c\/strong\u003e This oil seal is white in color.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow big is the Sierra 18-0564 oil seal?\u003c\/strong\u003e The Sierra 18-0564 measures 0.39 x 0.39 x 0.39 inches, a compact size intended for tight powerhead clearances.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0564 oil seal weigh?\u003c\/strong\u003e It weighs 0.01 pounds, making it a lightweight small-parts item.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0564 a universal-fit part?\u003c\/strong\u003e Yes, the 18-0564 oil seal is listed as a universal fit rather than being restricted to one specific engine model.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat finish does the Sierra 18-0564 oil seal have?\u003c\/strong\u003e The seal has a machined exterior finish, which supports a precise, consistent fit for sealing performance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0564 an aftermarket or genuine Mercury part?\u003c\/strong\u003e The 18-0564 is a Sierra-branded aftermarket oil seal that cross-references to and replaces Mercury Marine 26-888483.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat UPC is associated with the Sierra 18-0564 oil seal?\u003c\/strong\u003e The UPC for the Sierra 18-0564 oil seal is 808282200275.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the Sierra 18-0564 as a spare part for powerhead maintenance?\u003c\/strong\u003e Yes, due to its small size and low weight of 0.01 pounds, the 18-0564 oil seal is practical to keep on hand as a spare for outboard powerhead servicing.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078801115,"sku":"SIE-18-0564","price":19.71,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0564__83910.1737874349.500.750.jpg?v=1785189034"},{"product_id":"sierra-18-0577-carrier-assembly-oil-seal-replaces-mercruiser-66081a2-fits-alpha-one-gen-ii-upper-gear-housing","title":"Sierra 18-0577 Carrier Oil Seal Assembly, Replaces Mercruiser 66081A2, for Alpha One and Gen II Stern Drives","description":"\u003cp\u003eThe Sierra 18-0577 Carrier Oil Seal Assembly is a replacement seal for the upper gear housing carrier on MerCruiser stern drive units. It fits the 888\/228\/250\/260 series, the R and MR designations, Alpha One (including Alpha One SS and the counter-rotating CR versions), and Alpha One Gen II drives (including the CR versions). This seal assembly is a direct cross to Mercruiser 66081A2, 35993A1, 66081A1, and 66081A4, as well as GLM 28370 and Mallory 9-78100, so it can be used to service drives originally fitted with any of those parts.\u003c\/p\u003e\u003cp\u003eThe carrier oil seal keeps gear lube contained within the upper gear housing while preventing water intrusion at the drive shaft carrier, protecting the gear set from contamination and low-lubricant wear. It is typically installed as part of a routine upper gear housing seal kit service or whenever the carrier bearing\/seal area is opened up for repair. Sierra manufactures this part to meet or exceed the specification of the original equipment it replaces, and it is backed by Sierra's standard customer satisfaction warranty.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0577\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Carrier Oil Seal Assembly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercruiser Upper Gear Housing Seal Kits\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.2 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999973986\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGTIN:\u003c\/strong\u003e 00030999973986\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e GLM 28370, Mallory 9-78100, Mercruiser 66081A2, 35993A1, 66081A1, 66081A4\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMerCruiser 888\/228\/250\/260, 1977-1982\u003c\/li\u003e\n\u003cli\u003eMerCruiser R, 1983\u003c\/li\u003e\n\u003cli\u003eMerCruiser MR Alpha One, 1984-1990\u003c\/li\u003e\n\u003cli\u003eMerCruiser MR Alpha One (CR), 1984-1990\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One SS, 1986-1989\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II, 1991-1995\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II (CR), 1991-1995\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II, 1996-1997\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II (CR), 1996-2010\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 28370\u003c\/li\u003e\n\u003cli\u003eMallory 9-78100\u003c\/li\u003e\n\u003cli\u003eMercruiser 66081A2\u003c\/li\u003e\n\u003cli\u003eMercruiser 35993A1\u003c\/li\u003e\n\u003cli\u003eMercruiser 66081A1\u003c\/li\u003e\n\u003cli\u003eMercruiser 66081A4\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0577 Carrier Oil Seal Assembly fit?\u003c\/strong\u003e It fits MerCruiser stern drive units including the 888\/228\/250\/260 series (1977-1982), the R (1983) and MR (1984-1990) designations, Alpha One and Alpha One SS (1986-1989), and Alpha One Gen II drives (1991-2010), including the counter-rotating (CR) versions.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0577 seal a genuine OEM part or aftermarket?\u003c\/strong\u003e Sierra 18-0577 is a Sierra-manufactured replacement part, built to meet or exceed the original equipment specification for the Mercruiser carrier oil seal it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does Sierra 18-0577 cross to?\u003c\/strong\u003e This carrier oil seal assembly is interchangeable with Mercruiser 66081A2, 35993A1, 66081A1, and 66081A4, as well as GLM 28370 and Mallory 9-78100.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0577 fit both Alpha One and Alpha One Gen II drives?\u003c\/strong\u003e Yes, the 18-0577 carrier oil seal is used across Alpha One (1984-1990), Alpha One SS (1986-1989), and Alpha One Gen II (1991-2010) MerCruiser stern drives, including the CR variants.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0577 weigh?\u003c\/strong\u003e The Sierra 18-0577 Carrier Oil Seal Assembly weighs 0.2 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many pieces come in the 18-0577 package?\u003c\/strong\u003e The Sierra 18-0577 ships as a single carrier oil seal assembly, unit count of 1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the function of the carrier oil seal on a stern drive?\u003c\/strong\u003e The carrier oil seal seated in the upper gear housing keeps gear lubricant contained around the drive shaft carrier while blocking water intrusion, protecting the gear set from contamination and lubricant loss.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should the carrier oil seal be replaced?\u003c\/strong\u003e The 18-0577 carrier oil seal is typically replaced during a upper gear housing seal service, or any time the carrier bearing and seal area is opened up for repair or found to be leaking gear lube.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0577 fit the MerCruiser 888\/228\/250\/260 models?\u003c\/strong\u003e Yes, the Sierra 18-0577 is listed for the MerCruiser 888\/228\/250\/260 series produced 1977-1982.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0577 covered by a warranty?\u003c\/strong\u003e Sierra 18-0577, like other Sierra parts, is covered under Sierra's standard customer satisfaction warranty.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078866651,"sku":"SIE-18-0577","price":53.41,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0577_lg__38802.1558120940.500.750.jpg?v=1785188852"},{"product_id":"sierra-18-0578-rear-main-oil-seal-for-mercruiser-3-7l-4-cyl-replaces-mercruiser-26-67388","title":"Sierra 18-0578 One-Piece Rear Main Seal \/ Timing Cover Seal, Replaces 26-67388","description":"\u003cp\u003eThe Sierra 18-0578 is a one-piece rear main seal and timing cover seal built for marine engine crankshaft sealing applications. Its one-piece construction combines the rear main seal and timing cover seal function into a single component, simplifying installation compared to multi-piece seal designs and reducing the number of separate parts a technician needs to fit and align during an engine rebuild or reseal job. The seal has a white finish and a compact, low-profile design measuring 5.6 x 3.7 x 0.6 inches, with a light overall weight of 0.12 pounds that keeps it easy to handle during service work.\u003c\/p\u003e\u003cp\u003eThis seal directly replaces OEM part number 26-67388, making it a straightforward drop-in option when the original equipment seal needs replacement. Each Sierra seal is built to meet or exceed the specifications of the original equipment part it replaces, giving boat owners and marine technicians a reliable aftermarket alternative for crankshaft sealing repairs. It is engineered specifically for Mercruiser crankshaft sealing applications, and is sold as a single unit.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0578\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Rear Main Seal \/ Timing Cover Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDesign:\u003c\/strong\u003e One-Piece\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Marine Engine Crankshaft Sealing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e China\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 5.6 x 3.7 x 0.6 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.12 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999973993\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGTIN:\u003c\/strong\u003e 00030999973993\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-67388\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e Limited Warranty\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eEngineered for Mercruiser crankshaft sealing applications as a one-piece rear main seal and timing cover seal.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-67388\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the Sierra 18-0578 replace?\u003c\/strong\u003e The Sierra 18-0578 replaces OEM part number 26-67388, so it is a direct fit wherever that original seal was used.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0578 a one-piece or two-piece seal?\u003c\/strong\u003e It is a one-piece design that combines the rear main seal and timing cover seal into a single component, which simplifies installation versus a multi-piece seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0578 seal?\u003c\/strong\u003e It has a white finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow big is the Sierra 18-0578 seal?\u003c\/strong\u003e The Sierra 18-0578 measures 5.6 x 3.7 x 0.6 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0578 weigh?\u003c\/strong\u003e 0.12 pounds, making it easy to handle during installation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the Sierra 18-0578 manufactured?\u003c\/strong\u003e The country of origin listed for the Sierra 18-0578 is China.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0578 meet OEM specifications?\u003c\/strong\u003e Yes, the Sierra 18-0578 is built to meet or exceed the specifications of the original equipment seal it replaces, OEM 26-67388.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when you order the Sierra 18-0578?\u003c\/strong\u003e One Sierra 18-0578 one-piece rear main seal and timing cover seal (unit count of 1).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0578?\u003c\/strong\u003e The UPC is 030999973993.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat application is the Sierra 18-0578 designed for?\u003c\/strong\u003e The 18-0578 is engineered for Mercruiser crankshaft sealing applications as a rear main seal and timing cover seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0578 covered by a warranty?\u003c\/strong\u003e Yes, the Sierra 18-0578 carries a limited warranty.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988080177371,"sku":"SIE-18-0578","price":24.32,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0578_lg__30159.1558120992.500.750.jpg?v=1785188494"},{"product_id":"sierra-18-0579-oil-seal-replaces-mercury-force-26-41131-mercury-outboard-powerhead-seal","title":"Sierra Oil Seal 18-0579, Replaces Mercury 26-41131, White","description":"\u003cp\u003eThe Sierra 18-0579 Oil Seal is a rubber powerhead seal engineered to seal rotating shafts against oil and water intrusion in marine outboard and sterndrive powerheads. It is built to meet or exceed the specifications of the original equipment part it replaces, making it a reliable direct-fit choice for engine rebuilds and routine seal replacement. The seal is molded in white rubber and sized to a 1.313 inch outer diameter, a 1.141 inch shaft size, and a 0.344 inch width, allowing it to seat correctly in the powerhead bore while maintaining a tight, low-friction fit against the shaft. As a wear item, this seal is commonly replaced during powerhead teardowns, gearcase service, or whenever oil seepage is found around the shaft. It cross-references directly to Mercury and Chrysler\/Force\/US Marine part number 26-41131, giving buyers a straightforward way to confirm fit against their original part number before ordering.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0579\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Oil Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Rubber\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.313 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 1.141 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.344 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.04 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-41131\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDirect cross-reference to Mercury and Chrysler\/Force\/US Marine part number 26-41131; confirm against your original part number before ordering.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-41131\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0579 Oil Seal replace?\u003c\/strong\u003e The Sierra 18-0579 Oil Seal is a direct cross-reference to Mercury and Chrysler\/Force\/US Marine part number 26-41131.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0579 seal?\u003c\/strong\u003e This seal measures 1.313 inches outer diameter, 1.141 inches shaft size, and 0.344 inches in width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0579 Oil Seal made from?\u003c\/strong\u003e It is molded from rubber for durable sealing against oil and water in marine powerheads.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0579 seal?\u003c\/strong\u003e The 18-0579 seal is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0579 Oil Seal weigh?\u003c\/strong\u003e This seal weighs 0.04 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0579 seal equivalent to the original equipment part?\u003c\/strong\u003e Yes, Sierra states this oil seal meets or exceeds the original equipment part it replaces, part number 26-41131.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the 18-0579 seal typically installed?\u003c\/strong\u003e It is installed in the powerhead bore to seal a rotating shaft, and is commonly replaced during powerhead or gearcase service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many seals come in an order of 18-0579?\u003c\/strong\u003e The Sierra 18-0579 Oil Seal is supplied as a single unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace this seal?\u003c\/strong\u003e Oil seepage or leakage around the shaft during a powerhead teardown is the typical reason to replace the 18-0579 seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0579 seal fit non-Mercury applications?\u003c\/strong\u003e It cross-references to Mercury and Chrysler\/Force\/US Marine 26-41131, so any application originally using 26-41131 is a match.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988082045147,"sku":"SIE-18-0579","price":14.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-0579__39305.1722346079.500.750.jpg?v=1785188923"},{"product_id":"oil-seal-for-mercury-force-outboard-powerhead-replaces-26-41132-sierra-18-0580","title":"Sierra 18-0580 Oil Seal, Replaces Mercury\/Chrysler\/Force 26-41132","description":"\u003cp\u003eThe Sierra 18-0580 Oil Seal is a round, white oil seal engineered as a direct interchange for the 26-41132 seal used across multiple outboard powerhead applications. It is built to the same critical dimensions as the original equipment part it replaces, with a 1.250 inch outer diameter, a 0.750 inch shaft size, and a 0.312 inch width, so it seats and seals correctly in the same bore and against the same shaft as the part it replaces. As a powerhead seal, its primary job is to keep lubricating oil contained around a rotating shaft while excluding water and debris from the crankcase area, protecting internal components from contamination and oil loss.\u003c\/p\u003e\u003cp\u003eSierra manufactures this seal to meet or exceed the performance of the original equipment part, making it a straightforward replacement when an outboard's powerhead seal has hardened, cracked, or begun to leak. Because it is sold as a single seal, it drops in wherever a 26-41132 (or its cross-referenced equivalents) is specified, without requiring any modification to the surrounding housing.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0580\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-41132\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.250 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.750 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.312 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Mercury Outboard Powerhead Seals and O-Rings\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits applications originally specified with a 26-41132 oil seal or its cross-referenced equivalents.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-41132\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the Sierra 18-0580 oil seal replace?\u003c\/strong\u003e It replaces OEM number 26-41132. The Sierra 18-0580 oil seal is built to the same dimensions as that original part so it installs as a direct swap.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the Sierra 18-0580 oil seal?\u003c\/strong\u003e The Sierra 18-0580 measures 1.250 inches on the outer diameter, has a 0.750 inch shaft size, and is 0.312 inches wide.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0580 a genuine Sierra part or aftermarket?\u003c\/strong\u003e It is a Sierra-manufactured replacement seal, not a part sold under the original equipment manufacturer's own brand. Sierra states it meets or exceeds the performance of the original 26-41132 seal it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color and shape is the 18-0580 oil seal?\u003c\/strong\u003e It is a round seal finished in white, matching the standard oil seal shape used in outboard powerhead applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0580 oil seal weigh?\u003c\/strong\u003e The seal weighs 0.02 pounds, consistent with a small, single powerhead seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the purpose of the 18-0580 oil seal in an outboard powerhead?\u003c\/strong\u003e This seal keeps lubricating oil contained around a rotating shaft while keeping water and debris out of the crankcase area, protecting internal powerhead components from contamination and oil loss.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0580 come as a single seal or a kit?\u003c\/strong\u003e It is sold as a single oil seal, part number 18-0580, not as part of a multi-seal kit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the Sierra 18-0580 fit if my part is marked 26-41132?\u003c\/strong\u003e Yes, a part marked 26-41132 is the OEM number that the Sierra 18-0580 oil seal is designed to replace directly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if I need to replace an oil seal like the 18-0580?\u003c\/strong\u003e Signs of a failing powerhead oil seal include visible oil leakage around the shaft, water intrusion into the crankcase, or a hardened and cracked seal surface; the 18-0580 addresses these issues as a direct replacement for the 26-41132 seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of part is the Sierra 18-0580?\u003c\/strong\u003e The 18-0580 is categorized as a powerhead seal, part of Sierra's outboard powerhead seals and O-rings line.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988083781851,"sku":"SIE-18-0580","price":13.1,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0580_lg__51203.1558121135.500.750.jpg?v=1785189148"},{"product_id":"sierra-18-0586-oil-seal-replaces-mercury-chrysler-force-26-99325-outboard-powerhead-seal","title":"Sierra Oil Seal 18-0586, Replaces Chrysler Force 26-99325, Mercury Outboard Powerhead","description":"\u003cp\u003eThe Sierra 18-0586 Oil Seal is a precision-machined replacement seal engineered for Mercury outboard powerhead service, covering applications that trace back to Chrysler Force outboard motors now supported under the Mercury Marine parts line. This small but critical component seals against oil and water intrusion at rotating shaft interfaces within the powerhead, helping maintain proper lubrication pressure and preventing contamination that can lead to premature wear or corrosion inside the engine.\u003c\/p\u003e\u003cp\u003eBuilt to Sierra's marine-grade manufacturing standards, this seal is manufactured in Taiwan and machined to tight tolerances so it seats correctly and holds its seal under the vibration, heat cycling, and saltwater exposure typical of outboard powerhead operation. It is sold individually and is sized as a compact internal seal, making it a straightforward drop-in replacement during powerhead rebuilds, seal kit refreshes, or routine maintenance where the original seal has hardened, cracked, or begun leaking.\u003c\/p\u003e\u003cp\u003eBecause it carries the exact Sierra part number and cross-references directly to the original Chrysler Force equipment number, installers can order with confidence that they are getting a correct fit without needing to cross-check multiple aftermarket alternatives.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0586\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Oil Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-99325 (Chrysler Force)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercury Outboard Powerhead Seals and O-Rings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 6.35 cm L x 10.16 cm W x 0.254 cm H\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e Taiwan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eThis seal is cataloged for Mercury outboard powerhead service and is the correct replacement for Chrysler Force outboard applications using OEM number 26-99325. No specific engine model or year range is specified for this part; confirm your original seal's OEM number matches 26-99325 before ordering.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-99325 (Chrysler Force)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0586 oil seal replace?\u003c\/strong\u003e Sierra 18-0586 replaces the Chrysler Force OEM number 26-99325, so any powerhead calling for that original equipment number will accept this seal as a direct replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engine does the 18-0586 seal fit?\u003c\/strong\u003e The 18-0586 seal is cataloged for Mercury outboard powerhead applications that originally used Chrysler Force part 26-99325; no specific engine model or year range is listed, so confirm your existing seal's OEM number matches before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0586 oil seal weigh?\u003c\/strong\u003e It weighs 0.01 pounds, reflecting its compact size as an internal powerhead seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the Sierra 18-0586 seal?\u003c\/strong\u003e The seal itself measures 0.39 x 0.39 x 0.39 inches, and it ships in packaging measuring 6.35 cm L x 10.16 cm W x 0.254 cm H.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0586 an OEM part or an aftermarket replacement?\u003c\/strong\u003e The 18-0586 is a Sierra-manufactured aftermarket seal engineered as a direct cross-reference to Chrysler Force OEM number 26-99325, not an original Chrysler Force or Mercury part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the Sierra 18-0586 oil seal manufactured?\u003c\/strong\u003e This seal is manufactured in Taiwan under Sierra's marine parts program.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many seals come in a package of the 18-0586?\u003c\/strong\u003e The 18-0586 is packaged and sold individually, with a package quantity of 1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the difference between the 18-0586 seal and the original Chrysler Force seal?\u003c\/strong\u003e Functionally the 18-0586 is built to match the original Chrysler Force 26-99325 seal for fit and sealing performance; the main difference is that it is produced under the Sierra brand rather than the original Chrysler Force label.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-0586 be used in a powerhead rebuild kit?\u003c\/strong\u003e Yes, the 18-0586 oil seal is suited to powerhead rebuild and maintenance work anywhere the Chrysler Force 26-99325 seal is specified.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0586 seal include installation hardware?\u003c\/strong\u003e No, the 18-0586 is supplied as the seal component only, with a package quantity of 1 and no additional hardware included.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I confirm the 18-0586 is the correct seal for my outboard?\u003c\/strong\u003e Check the OEM number stamped on your existing seal or listed in your engine's parts manual against 26-99325; if it matches, Sierra 18-0586 is the correct replacement.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988083814619,"sku":"SIE-18-0586","price":11.56,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-0586__96423.1675866227.500.750.jpg?v=1785188924"},{"product_id":"sierra-18-0583-marine-oil-seal-for-honda-outboard-gearcase-replaces-26-43035-honda-91251-zw1-003","title":"Sierra 18-0583 Marine Oil Seal, Replaces 26-43035, 1.063 Inch Shaft","description":"\u003cp\u003eThe Sierra 18-0583 Marine Oil Seal is a precision-machined replacement seal designed for outboard and stern drive gearcase and drive applications, including Honda outboard gearcase and drive service. It seals the shaft bore to keep gear lubricant contained and water out, protecting internal gearcase components from contamination and lubricant loss. The seal is built to meet or exceed the performance of the original equipment part it replaces, making it a reliable choice for gearcase rebuilds, lower unit service, and routine maintenance.\u003c\/p\u003e\u003cp\u003eWith an outer diameter of 1.496 inches (38 mm), a shaft size of 1.063 inches (27 mm), and a width of 0.197 inches (5 mm), the 18-0583 is sized for a specific gearcase bore and shaft combination, so confirming these dimensions against your existing seal or service manual before ordering is recommended. The seal carries a machined exterior finish for a consistent, reliable fit during installation.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0583\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.496 inches (38 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 1.063 inches (27 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.197 inches (5 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282242732\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e 26-43035\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Honda Outboard Gearcase and Drive Parts\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for outboard gearcase and drive applications, including Honda outboard gearcase and drive service. Confirm the outer diameter, shaft size, and width against your unit before ordering.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-43035\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0583 oil seal fit?\u003c\/strong\u003e The Sierra 18-0583 is built for outboard gearcase and drive applications, including Honda outboard gearcase and drive service, and it should be matched to your unit by outer diameter, shaft size, and width before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size is the 18-0583 oil seal?\u003c\/strong\u003e It measures 1.496 inches (38 mm) outer diameter, 1.063 inches (27 mm) shaft size, and 0.197 inches (5 mm) width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0583 replace OEM part 26-43035?\u003c\/strong\u003e Yes, the Sierra 18-0583 is the cross-reference equivalent to OEM part number 26-43035.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0583 oil seal weigh?\u003c\/strong\u003e This oil seal weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0583 a genuine OEM part or aftermarket?\u003c\/strong\u003e It is a Sierra-brand aftermarket replacement seal engineered to meet or exceed the performance of the original equipment part it replaces, identified by OEM cross-reference 26-43035.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat finish does the 18-0583 seal have?\u003c\/strong\u003e The Sierra 18-0583 has a machined exterior finish for a consistent, reliable fit during installation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the 18-0583 seal for a gearcase rebuild?\u003c\/strong\u003e Yes, this seal is commonly used in gearcase and lower unit rebuilds and routine drive maintenance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-0583?\u003c\/strong\u003e Each order includes one Sierra 18-0583 marine oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of parts does the 18-0583 belong to?\u003c\/strong\u003e The Sierra 18-0583 is categorized as a Honda outboard gearcase and drive part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I confirm the 18-0583 is the correct seal for my gearcase?\u003c\/strong\u003e Compare the outer diameter (1.496 inches), shaft size (1.063 inches), and width (0.197 inches) of the 18-0583 against the seal currently installed in your gearcase or drive.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988083847387,"sku":"SIE-18-0583","price":11.94,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0583_lg__96923.1558121272.500.750.jpg?v=1785188296"},{"product_id":"sierra-18-0659-o-ring-for-pressure-control-valve-yamaha-outboard-gearcase-drive","title":"Sierra O-Ring for Pressure Control Valve, Part Number 18-0659","description":"\u003cp\u003eThis is a genuine Sierra O-ring engineered specifically for the pressure control valve on marine engine applications. It is designed as a direct seal replacement, restoring proper sealing at the pressure control valve where an original O-ring has hardened, cracked, or lost its seal over time. As a small, single-component seal, its role is simple but critical: prevent pressure loss and leakage at the valve interface, helping the pressure control valve function as intended. Each unit is sold as a single O-ring identified by Sierra part number 18-0659.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0659\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Type:\u003c\/strong\u003e O-Ring, Pressure Control Valve\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282388775\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 O-ring per pack\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is Sierra part 18-0659 used for?\u003c\/strong\u003e Sierra 18-0659 is an O-ring designed to seal the pressure control valve on a marine engine, replacing a worn or damaged original seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many O-rings come in one order of 18-0659?\u003c\/strong\u003e Each order of Sierra 18-0659 includes one O-ring, sold as a single unit for one pressure control valve.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0659 a genuine Sierra part?\u003c\/strong\u003e Yes, 18-0659 is a genuine Sierra O-ring, not a generic or universal seal, made specifically for the pressure control valve application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0659 O-ring weigh?\u003c\/strong\u003e The Sierra 18-0659 O-ring weighs 0.01 pounds, reflecting its small size as a single seal component.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for Sierra 18-0659?\u003c\/strong\u003e The UPC for the Sierra 18-0659 pressure control valve O-ring is 808282388775.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the pressure control valve O-ring?\u003c\/strong\u003e Replace the O-ring on the pressure control valve, such as Sierra 18-0659, if you notice a loss of pressure, fluid seepage around the valve, or a visibly cracked or flattened seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes 18-0659 include the pressure control valve itself?\u003c\/strong\u003e No, this part covers only the O-ring seal for the pressure control valve, not the valve body or assembly itself.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan 18-0659 be used as a general-purpose O-ring?\u003c\/strong\u003e Sierra 18-0659 is manufactured specifically for the pressure control valve application rather than as a generic all-purpose seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs installation of the 18-0659 O-ring simple?\u003c\/strong\u003e Installing the Sierra 18-0659 O-ring is a straightforward seal replacement at the pressure control valve, requiring removal of the old O-ring and seating the new one in its place.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy choose the Sierra 18-0659 over a generic O-ring?\u003c\/strong\u003e The Sierra 18-0659 is sized and specified for the pressure control valve, so it fits and seals correctly where a generic O-ring may not match the required dimensions.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988083912923,"sku":"SIE-18-0659","price":4.14,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-0659__89853.1739477160.500.750.jpg?v=1785188985"},{"product_id":"sierra-18-0595-oil-seal-for-mercury-outboard-powerhead-replaces-mercury-26-66303-1-125-in-od","title":"Sierra Oil Seal 18-0595, Replaces Mercury Marine 26-66303","description":"\u003cp\u003eThe Sierra 18-0595 is an oil seal engineered for Mercury outboard powerheads, providing a reliable barrier against oil leakage at the shaft. It is built with a 1.125 inch outer diameter and a 0.688 inch shaft size, sized to fit precisely into the powerhead seal bore it is designed for. At only 0.250 inches wide, it is a compact component intended to sit flush within its mounting location without interference from surrounding parts.\u003c\/p\u003e\u003cp\u003eThis seal directly replaces Mercury Marine part number 26-66303, making it a straightforward drop-in option for powerhead seal replacement and rebuild work. Sierra parts are constructed with quality materials aimed at delivering dependable service life and consistent sealing performance in the marine environment. The 18-0595 falls under Sierra's Mercury Outboard Powerhead Seals \u0026amp; O-Rings category, reflecting its specific application in outboard powerhead assemblies where maintaining oil containment is critical to engine protection.\u003c\/p\u003e\u003cp\u003eAt just 0.02 pounds, this is a small, lightweight part that is easy to keep on hand as a maintenance spare. Whether performing a full powerhead rebuild or addressing an isolated oil seal failure, the 18-0595 gives technicians and boat owners a Sierra-manufactured alternative to the OEM Mercury Marine part.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0595\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Oil Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercury Outboard Powerhead Seals \u0026amp; O-Rings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.125 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.688 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.250 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282233983\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e Mercury Marine 26-66303\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury outboard powerheads using Mercury Marine oil seal 26-66303\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-66303\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0595 oil seal replace?\u003c\/strong\u003e The Sierra 18-0595 directly replaces Mercury Marine part number 26-66303, so it can be installed anywhere that Mercury Marine seal is called for.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the outer diameter of the 18-0595 oil seal?\u003c\/strong\u003e The outer diameter is 1.125 inches, which is the size of the seal's outer edge that seats into the powerhead bore.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shaft size does this Sierra oil seal fit?\u003c\/strong\u003e It is sized for a 0.688 inch shaft, matching the shaft diameter it seals against on Mercury outboard powerheads.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow wide is the Sierra 18-0595 seal?\u003c\/strong\u003e 0.250 inches wide, a compact dimension intended to fit flush within its designated seal location.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0595 oil seal weigh?\u003c\/strong\u003e It weighs 0.02 pounds, a very light single-component part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0595?\u003c\/strong\u003e The UPC is 808282233983, which can be used to confirm you are ordering the correct oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0595 an OEM part or an aftermarket replacement?\u003c\/strong\u003e It is a Sierra-manufactured replacement seal built to replace Mercury Marine 26-66303, not an OEM Mercury Marine part itself, though it is designed as a direct equivalent.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat application is the 18-0595 oil seal used on?\u003c\/strong\u003e It is listed under Mercury Outboard Powerhead Seals \u0026amp; O-Rings, indicating its use in Mercury outboard powerhead assemblies.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when you order the 18-0595?\u003c\/strong\u003e Each order includes one Sierra 18-0595 oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0595 suitable for a powerhead rebuild?\u003c\/strong\u003e Yes, its role as a powerhead seal replacing Mercury Marine 26-66303 makes it applicable to powerhead rebuild and repair work.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988083945691,"sku":"SIE-18-0595","price":9.56,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0595_lg__09089.1558118637.500.750.jpg?v=1785189109"},{"product_id":"reed-plate-gasket-for-mercury-outboards-replaces-27-14697-2-sierra-18-0644","title":"Sierra 18-0644 Reed Plate Gasket for Mercury Outboards, Replaces 27-146972","description":"\u003cp\u003eThe Sierra 18-0644 Reed Plate Gasket is a replacement gasket engineered to seal the reed plate assembly on applicable Mercury outboard engines. It is built to meet or exceed the quality of the original equipment part it replaces, giving boaters a reliable seal that helps maintain proper crankcase compression and prevent air leaks at the reed block interface. The gasket is white in color and is sized to match the original reed plate mounting surface it is designed for.\u003c\/p\u003e\u003cp\u003eReed plate gaskets are a wear item that should be replaced any time the reed valve assembly is removed for inspection or service, since a used gasket can lose its ability to seal properly once disturbed. Installing a fresh Sierra 18-0644 gasket during reed plate maintenance helps restore a tight seal between mating surfaces and supports consistent engine performance. This part cross-references directly to GLM 37530 and Mercury 27-146972, making it straightforward to identify as a correct match when replacing a worn or damaged original gasket.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0644\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Reed Plate Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282242824\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.2 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 0.508 centimeters H x 17.78 centimeters L x 35.56 centimeters W\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e China\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e GLM 37530, Mercury 27-146972\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eSpecific engine models and year ranges are not specified for this part; it is cross-referenced to GLM 37530 and Mercury 27-146972.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 37530\u003c\/li\u003e\n\u003cli\u003eMercury 27-146972\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0644 Reed Plate Gasket used for?\u003c\/strong\u003e It seals the reed plate assembly on applicable Mercury outboard engines, helping maintain proper compression and preventing air leaks at the reed block.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0644 gasket cross-reference to any OEM numbers?\u003c\/strong\u003e Yes, the Sierra 18-0644 is interchangeable with GLM 37530 and Mercury 27-146972.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0644 equivalent to the Mercury 27-146972 gasket?\u003c\/strong\u003e Yes, Mercury 27-146972 is a direct cross-reference for the Sierra 18-0644 Reed Plate Gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the reed plate gasket?\u003c\/strong\u003e The Sierra 18-0644 Reed Plate Gasket is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0644 gasket weigh?\u003c\/strong\u003e It weighs 0.2 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the package dimensions of the Sierra 18-0644 gasket?\u003c\/strong\u003e The package measures 0.508 centimeters H by 17.78 centimeters L by 35.56 centimeters W.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the Sierra 18-0644 Reed Plate Gasket manufactured?\u003c\/strong\u003e The country of origin for the Sierra 18-0644 is China.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part or aftermarket?\u003c\/strong\u003e The 18-0644 is a genuine Sierra branded part, manufactured to meet or exceed the quality of the original equipment gasket it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should the reed plate gasket be replaced?\u003c\/strong\u003e Any time the reed valve assembly on the outboard is removed for inspection or service, since a used gasket can lose its ability to seal once disturbed; the Sierra 18-0644 is designed as a fresh replacement for that job.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when ordering part 18-0644?\u003c\/strong\u003e The order includes one Sierra 18-0644 Reed Plate Gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the GLM 37530 gasket the same as the Sierra 18-0644?\u003c\/strong\u003e Yes, GLM 37530 is listed as an interchangeable cross-reference for the Sierra 18-0644 Reed Plate Gasket.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988083978459,"sku":"SIE-18-0644","price":10.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0644_lg__79096.1558120179.500.750.jpg?v=1785188267"},{"product_id":"oil-seal-housing-gasket-for-suzuki-f25-v-twin-2006-2007-replaces-oem-56132-95j00","title":"Sierra Drain Plug Gasket 09168-10022 Replacement for Suzuki Outboards, Package of 5","description":"\u003cp\u003eThis Sierra drain plug gasket, part number 18-0650, is a direct-fit sealing gasket designed for Suzuki outboard motor drain plug applications. It creates a reliable seal at the drain plug to prevent oil or fluid leaks during routine maintenance and oil changes. Each gasket is a direct cross-reference replacement for OEM number 09168-10022, so it installs the same way the original factory gasket did, with no modification needed.\u003c\/p\u003e\u003cp\u003eSold as a package of 5, this gasket lets boat owners and marine technicians keep spares on hand for scheduled maintenance intervals, since drain plug gaskets are a wear item that should be replaced each time the drain plug is removed to maintain a proper seal. Using a fresh gasket at every oil change helps prevent weeping or leaking at the drain plug and protects against contamination of the lower unit or crankcase.\u003c\/p\u003e\u003cp\u003eAs a Sierra part, this gasket is built to match OEM specifications for fit and sealing performance on applicable Suzuki outboard motors.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0650\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Drain Plug Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 5 gaskets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282226619\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eSuzuki outboard motors.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e09168-10022\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does Sierra part 18-0650 replace?\u003c\/strong\u003e Sierra 18-0650 is a direct cross-reference replacement for OEM part number 09168-10022, so it can be installed anywhere that OEM gasket is called for.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in a package of 18-0650?\u003c\/strong\u003e Each package contains 5 drain plug gaskets, giving you enough spares for multiple oil changes or services.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the weight of the Sierra 18-0650 gasket package?\u003c\/strong\u003e The Sierra 18-0650 drain plug gasket package weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is Sierra 18-0650 used for?\u003c\/strong\u003e It is a drain plug gasket used to create a seal at the drain plug on applicable Suzuki outboard motors, preventing oil or fluid leaks.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShould the drain plug gasket be replaced every oil change?\u003c\/strong\u003e Yes, drain plug gaskets like Sierra 18-0650 are a wear item and should be replaced each time the drain plug is removed to maintain a proper seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0650 an OEM or aftermarket part?\u003c\/strong\u003e Sierra 18-0650 is an aftermarket gasket manufactured to match the fit and seal of OEM part 09168-10022.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat outboard brand is Sierra 18-0650 designed for?\u003c\/strong\u003e This gasket is designed for use on Suzuki outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order Sierra 18-0650?\u003c\/strong\u003e Ordering Sierra 18-0650 gets you a package of 5 individual drain plug gaskets, with no additional hardware included.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan Sierra 18-0650 be used for other applications besides the drain plug?\u003c\/strong\u003e Sierra 18-0650 is specified as a drain plug gasket cross-referencing OEM 09168-10022, so it is intended for drain plug sealing applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy buy a 5-pack instead of a single drain plug gasket?\u003c\/strong\u003e Buying the 5-pack of Sierra 18-0650 gaskets lets you keep spares on hand since a new gasket is recommended at every drain plug removal, reducing the need for repeat orders.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988084076763,"sku":"SIE-18-0650","price":2.59,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0650_lg__12931.1558120522.500.750.jpg?v=1785329155"},{"product_id":"sierra-18-0614-marine-oil-pan-for-mercruiser-gm-big-block-v8-replaces-845668t-850458-811549-right-hand-dipstick","title":"Sierra 18-0614 Rear Main Seal, Replaces Mercruiser 845668T, for GM Big Block V8 (Right Handed Dipstick)","description":"\u003cp\u003eThe Sierra 18-0614 is a 1-piece rear main seal engineered for GM Big Block V8 marine engines equipped with a right-handed dipstick. Installed at the rear of the crankshaft where it meets the flywheel housing, this seal keeps engine oil contained and prevents leaks at one of the most common failure points on inboard and sterndrive engines. Its 1-piece design simplifies installation compared to older 2-piece seal setups, reducing the number of parting lines that can become a leak path over time.\u003c\/p\u003e\u003cp\u003eSierra builds this seal to fit as a direct equivalent for the Mercruiser rear main seals it replaces, so it installs using the same engine preparation and hardware as the original part. It is intended for use during rear main seal replacement, engine rebuilds, or any repair where oil is leaking from the rear of the crankshaft on a GM Big Block V8 marine engine with a right-handed dipstick configuration.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0614\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Rear Main Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeal Design:\u003c\/strong\u003e 1-piece\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e GM Big Block V8 (Right Handed Dipstick)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 13.63 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 845668T, 850458, 811549\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercruiser GM Big Block V8 engines with right-handed dipstick configuration\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e845668T\u003c\/li\u003e\n\u003cli\u003e850458\u003c\/li\u003e\n\u003cli\u003e811549\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0614 rear main seal fit?\u003c\/strong\u003e The Sierra 18-0614 is designed for GM Big Block V8 marine engines with a right-handed dipstick configuration.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0614 a 1-piece or 2-piece rear main seal?\u003c\/strong\u003e It is a 1-piece rear main seal, which uses a single continuous seal rather than two separate seal halves.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does the Sierra 18-0614 replace?\u003c\/strong\u003e It replaces Mercruiser rear main seal part numbers 845668T, 850458, and 811549.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the Sierra 18-0614 work on a GM Big Block V8 with a left-handed dipstick?\u003c\/strong\u003e No. The 18-0614 is built for the right-handed dipstick configuration; GM Big Block V8 engines with a different dipstick placement require a different Sierra rear main seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0614 rear main seal weigh?\u003c\/strong\u003e The Sierra 18-0614 has a shipping weight of 13.63 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen would I need to replace this rear main seal?\u003c\/strong\u003e Replacement is needed when oil is leaking from the rear of the crankshaft near the flywheel housing on a GM Big Block V8 marine engine, or during an engine rebuild.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0614 an OEM part or an aftermarket replacement?\u003c\/strong\u003e The 18-0614 is a Sierra-manufactured replacement seal designed to cross-reference directly to Mercruiser OEM numbers 845668T, 850458, and 811549.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes installing a 1-piece rear main seal require different tools than a 2-piece seal?\u003c\/strong\u003e The Sierra 18-0614's 1-piece design installs using standard rear main seal installation procedures for GM Big Block V8 engines; no special tools beyond standard seal installation are implied by its design.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat brand makes the 18-0614 rear main seal?\u003c\/strong\u003e The 18-0614 is manufactured by Sierra.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the Sierra 18-0614 to cross-reference a Mercruiser 850458 seal?\u003c\/strong\u003e Yes, Mercruiser 850458 is one of the OEM numbers the Sierra 18-0614 directly replaces.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988084109531,"sku":"SIE-18-0614","price":354.67,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/Untitled-1__36729.1753452632.500.750.jpg?v=1785188597"},{"product_id":"sierra-18-0612-marine-oil-pan-for-mercruiser-gm-small-block-v8-replaces-809910-14259-1-piece-rear-main-seal-rh-dipstick","title":"Sierra Rear Main Seal 18-0612 - Replaces Mercruiser 809910, 14259 - GM Small Block V8","description":"\u003cp\u003eThe Sierra 18-0612 is a one-piece rear main seal engineered for GM Small Block V8 engines built with a right-handed dipstick, as used in Mercruiser sterndrive applications. This seal fits between the engine block and the crankshaft flange at the rear of the engine, sealing the crankshaft bore to keep engine oil from leaking past the crankcase. Sierra manufactures the 18-0612 to OEM interchange standards so it installs as a direct equivalent without requiring modification, cross-referencing to Mercruiser OEM numbers 809910 and 14259.\u003c\/p\u003e\u003cp\u003eThe 18-0612 is one of several rear main seals in Sierra's lineup, each matched to a specific engine family and dipstick orientation. Because the correct seal depends on whether the block is GM Small Block, Big Block, or V6, and whether the dipstick is left- or right-handed, ordering the exact part number for your engine is important to get a proper seal. The 18-0612 is specifically the one-piece design for GM Small Block V8 engines with a right-handed dipstick.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0612\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Rear Main Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeal Type:\u003c\/strong\u003e 1-Piece\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Compatibility:\u003c\/strong\u003e GM Small Block V8 (Right Handed Dipstick)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 809910, 14259\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 7.48 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercruiser sterndrive engines: GM Small Block V8 (Right Handed Dipstick)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e809910\u003c\/li\u003e\n\u003cli\u003e14259\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0612 rear main seal fit?\u003c\/strong\u003e The 18-0612 is a one-piece rear main seal built for GM Small Block V8 engines with a right-handed dipstick, as used in Mercruiser sterndrive applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0612 a one-piece or two-piece seal?\u003c\/strong\u003e One piece. The 18-0612 uses a single-piece rear main seal design, while Sierra's 18-0613 is the two-piece version built for the same GM Small Block V8 engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich OEM numbers does the 18-0612 replace?\u003c\/strong\u003e It replaces Mercruiser OEM numbers 809910 and 14259.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the 18-0612 fit a GM Big Block V8?\u003c\/strong\u003e No. Big block V8 applications use Sierra 18-0614 (one-piece) or 18-0615 (two-piece); the 18-0612 is built specifically for GM Small Block V8 engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy does the dipstick side matter for this seal?\u003c\/strong\u003e GM Small Block V8 engines are produced in both left- and right-handed dipstick configurations, and the 18-0612 is engineered for the right-handed dipstick version, so it must be matched to that configuration to seal properly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0612 weigh?\u003c\/strong\u003e The Sierra 18-0612 rear main seal weighs 7.48 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part or an aftermarket copy?\u003c\/strong\u003e The 18-0612 is manufactured by Sierra to OEM specifications as a direct replacement for Mercruiser 809910 and 14259.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-0612?\u003c\/strong\u003e Each order of the 18-0612 includes one rear main seal unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0612 work on a GM V6 engine?\u003c\/strong\u003e No. GM V6 engines use the separate Sierra 18-0616 rear main seal; the 18-0612 is designed only for GM Small Block V8 engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat Mercruiser engines use the 18-0612 seal?\u003c\/strong\u003e Mercruiser GM Small Block V8 engines with a right-handed dipstick use the 18-0612, which cross-references to OEM 809910 and 14259.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is the 18-0612 different from the 18-0614?\u003c\/strong\u003e The 18-0612 is the one-piece rear main seal for GM Small Block V8 engines, while the 18-0614 is the corresponding one-piece seal for GM Big Block V8 engines; the two are not interchangeable.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0612 sold as a single seal?\u003c\/strong\u003e Yes, the Sierra 18-0612 rear main seal ships as a single unit weighing 7.48 pounds.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988084338907,"sku":"SIE-18-0612","price":356.61,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-0612___20184.1753840673.500.750.jpg?v=1785188140"},{"product_id":"sierra-18-0645-reed-plate-gasket-for-mercury-mariner-outboard-replaces-oem-27-14697-2","title":"Sierra 18-0645 Adapter Plate Gasket for Mercury\/Mariner Outboard Motors, White","description":"\u003cp\u003eThe Sierra 18-0645 Adapter Plate Gasket is a replacement gasket engineered for Mercury and Mariner outboard motors. It seals the adapter plate joint on the powerhead, helping maintain a proper seal against water and combustion gases so the engine runs as designed. The gasket is manufactured to OEM specifications, meaning it is built to meet or exceed the performance of the original equipment part it replaces, giving boat owners a dependable option when servicing the adapter plate area during a rebuild, tune-up, or routine maintenance.\u003c\/p\u003e\u003cp\u003eFinished in white and featuring a round profile to match the adapter plate mounting pattern, this gasket is designed for a straightforward, direct-fit installation without modification. Sierra builds this part to stand up to the demanding conditions of the marine environment, including exposure to fuel, oil, heat, and moisture, so it holds its seal over time. As a fit type listed as universal for Mercury\/Mariner outboard applications, it is a practical replacement part to keep on hand for outboard maintenance and repair work.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0645\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercury Outboard Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e OEM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFit Type:\u003c\/strong\u003e Universal Fit for Mercury\/Mariner outboard motors\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282242831\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury\/Mariner outboard motors (universal fit)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0645 gasket used for?\u003c\/strong\u003e It is an adapter plate gasket that seals the adapter plate joint on Mercury and Mariner outboard motors, helping maintain a proper seal during engine operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0645 gasket fit all Mercury and Mariner outboards?\u003c\/strong\u003e It is listed as a universal fit for Mercury\/Mariner outboard motors rather than being restricted to one specific model or year range.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-0645 adapter plate gasket?\u003c\/strong\u003e The gasket is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape is the Sierra 18-0645 gasket?\u003c\/strong\u003e It has a round shape, matching the adapter plate mounting pattern it is designed to seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0645 gasket weigh?\u003c\/strong\u003e The Sierra 18-0645 adapter plate gasket weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0645 gasket an OEM part or aftermarket?\u003c\/strong\u003e It is an aftermarket gasket manufactured to OEM specifications, meaning it is built to meet or exceed the performance of the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0645 gasket made from?\u003c\/strong\u003e It is made to OEM material specifications for the adapter plate application on Mercury\/Mariner outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I install the 18-0645 gasket myself?\u003c\/strong\u003e Yes, it is designed as a direct-fit replacement for the adapter plate joint, suitable for use during a standard powerhead service or rebuild.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order part number 18-0645?\u003c\/strong\u003e The order includes one Sierra adapter plate gasket, part number 18-0645.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy choose the Sierra 18-0645 over a generic gasket?\u003c\/strong\u003e Sierra manufactures the 18-0645 to meet or exceed the specifications of the original equipment part, offering a dependable seal for the marine environment rather than a generic substitute.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988084371675,"sku":"SIE-18-0645","price":9.38,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0645_lg__06291.1558120251.500.750.jpg?v=1785188089"},{"product_id":"sierra-18-0664-marine-valve-cover-gasket-replaces-mercury-27-17467-omc-3852687-fits-gm-305-350-5-0l-5-7l","title":"Sierra 18-0664 Valve Cover Gasket, Replaces 909529, Fits GM 305\/350 5.0L \u0026 5.7L Engines","description":"\u003cp\u003eThe Sierra 18-0664 is a valve cover gasket engineered to seal the valve cover against the cylinder head on GM 305\/350 cubic-inch marine engines, including 5.0L and 5.7L applications. It creates the seal that keeps oil inside the valve cover assembly and prevents leaks at the cylinder head mating surface, a common failure point on inboard and sterndrive engines that see extended run time and heat cycling.\u003c\/p\u003e\u003cp\u003eEach 18-0664 is sold as a pack of 2, giving you both gaskets needed for a V8 engine's left and right valve covers in a single purchase. Replacing worn valve cover gaskets is a routine maintenance step during valve cover removal for inspection, tappet adjustment, or general engine service, and using a properly sized replacement gasket helps ensure a leak-free reseal.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0664\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Valve Cover Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 2 gaskets per pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e GM 305\/350, 5.0L \u0026amp; 5.7L engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.29 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282237189\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGM 305\/350 cubic-inch engines\u003c\/li\u003e\n\u003cli\u003e5.0L and 5.7L engines\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e909529\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0664 fit?\u003c\/strong\u003e The Sierra 18-0664 valve cover gasket fits GM 305\/350 cubic-inch engines, including 5.0L and 5.7L versions.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0664 the same gasket as OEM 909529?\u003c\/strong\u003e Yes, the Sierra 18-0664 replaces OEM part number 909529 and is designed as a direct-fit substitute for it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets are included with part 18-0664?\u003c\/strong\u003e Part 18-0664 is packaged as a set of 2 gaskets, enough to cover both valve covers on a V8 engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0664 gasket weigh?\u003c\/strong\u003e The Sierra 18-0664 valve cover gasket has a shipping weight of 0.29 pounds for the 2-gasket pack.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need one or two gaskets for my engine?\u003c\/strong\u003e A V8 engine has two valve covers, so you need two gaskets, which is exactly what comes in one pack of the Sierra 18-0664.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part?\u003c\/strong\u003e Yes, this gasket is manufactured and sold under the Sierra brand as part number 18-0664.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I reuse a valve cover gasket after removing the valve cover?\u003c\/strong\u003e Gaskets are generally not reused once removed since they lose their sealing compression; installing a new Sierra 18-0664 gasket at reassembly gives the most reliable seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the function of the valve cover gasket on a GM 305\/350 engine?\u003c\/strong\u003e It seals the joint between the valve cover and the cylinder head, part number 18-0664 being the gasket sized for GM 305\/350, 5.0L and 5.7L engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0664 come as a full gasket set or just the valve cover gasket?\u003c\/strong\u003e The Sierra 18-0664 is specifically a valve cover gasket, sold two to a pack, and is not a complete engine gasket set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM number should I cross-reference when ordering 18-0664?\u003c\/strong\u003e Sierra 18-0664 cross-references to OEM part number 909529.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988084404443,"sku":"SIE-18-0664","price":26.56,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0664_lg__88774.1558120740.500.750.jpg?v=1785188797"},{"product_id":"sierra-18-0767-water-jacket-cover-gasket-for-yamaha-outboard-replaces-oem-688-11193-01-00","title":"Sierra Water Jacket Cover Gasket 18-0767 for Yamaha Outboard Engines","description":"\u003cp\u003eThe Sierra Water Jacket Cover Gasket, part number 18-0767, is a replacement gasket engineered to seal the water jacket cover on applicable Yamaha outboard engines. Positioned in the cooling passage assembly, this gasket creates a reliable seal between the water jacket cover and the engine block, helping prevent coolant leaks and maintain proper cooling system pressure. Installing a correctly sized, properly fitted gasket at this joint is essential to keeping raw water or coolant contained within the intended passages during engine operation.\u003c\/p\u003e\u003cp\u003eThis gasket is manufactured to precise dimensions for a consistent, drop-in fit at the water jacket cover interface. Sierra Marine produces this part under its own part numbering system for the marine aftermarket, giving boat owners and marine technicians a dedicated replacement option when servicing the cooling system on a Yamaha outboard. Because gaskets are wear items that harden, compress, or degrade with heat cycling and time, replacing the water jacket cover gasket whenever the cover is removed for inspection or service helps ensure a leak-free reseal.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0767\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Category:\u003c\/strong\u003e Yamaha Outboard Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874641\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.22 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eDesigned for applicable Yamaha outboard engines (water jacket cover application)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eNo verified OEM cross-reference number is available for this part\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0767 gasket used for?\u003c\/strong\u003e It seals the water jacket cover on applicable Yamaha outboard engines, sitting between the cover and the engine block to help contain coolant within the cooling passages.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0767 gasket a genuine Sierra part?\u003c\/strong\u003e Yes, 18-0767 is Sierra's own part number for this Water Jacket Cover Gasket, manufactured for the marine aftermarket rather than sold under a third-party label.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size is the Sierra Water Jacket Cover Gasket?\u003c\/strong\u003e The gasket measures 0.39 x 0.39 x 0.39 inches and weighs 0.22 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich engines does part number 18-0767 fit?\u003c\/strong\u003e This gasket is designed for the water jacket cover application on applicable Yamaha outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes Sierra list an OEM cross-reference number for 18-0767?\u003c\/strong\u003e No verified OEM cross-reference number is documented for the Sierra 18-0767 Water Jacket Cover Gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if I need to replace this gasket?\u003c\/strong\u003e Coolant or water seepage around the water jacket cover, visible gasket hardening, or a compressed\/damaged gasket surface after removing the cover are signs the 18-0767 gasket should be replaced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I reuse the old gasket when reinstalling the water jacket cover?\u003c\/strong\u003e It is best practice to install a new gasket, such as the Sierra 18-0767, any time the water jacket cover is removed, since gaskets are designed as one-time-use sealing components.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat comes in the package with part 18-0767?\u003c\/strong\u003e The listing includes one Sierra Water Jacket Cover Gasket, part number 18-0767.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this gasket sold individually or as part of a kit?\u003c\/strong\u003e Part number 18-0767 is sold as a single, individual Water Jacket Cover Gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is the Sierra 18-0767 different from a generic aftermarket gasket?\u003c\/strong\u003e It carries Sierra's own manufacturer part number and is produced to defined dimensions specifically for the water jacket cover application on applicable Yamaha outboards, rather than being a generic, unspecified-fit gasket.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988085649627,"sku":"SIE-18-0767","price":18.7,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0767_lg__43009.1660051588.500.750.jpg?v=1785188485"},{"product_id":"sierra-18-0779-water-jacket-gasket-for-yamaha-outboards-replaces-oem-6g5-11193-a0-00","title":"Sierra 18-0779 Water Jacket Gasket for Yamaha Outboards - Replaces 6G5-11193-A0-00","description":"\u003cp\u003eThe Sierra 18-0779 Water Jacket Gasket is a replacement gasket engineered for Yamaha outboard engines, sealing the water jacket to maintain proper cooling system integrity. Manufactured to meet or exceed original equipment quality, this gasket is a direct interchange for Yamaha part number 6G5-11193-A0-00. Each engine application requires 2 of these gaskets to complete the water jacket seal properly, so buyers should order accordingly for a full repair. The gasket is finished in white and is sold as a single unit per package. Sierra manufactures its marine gaskets to original equipment tolerances, helping ensure a proper seal against coolant leaks and preventing overheating issues caused by a failed or degraded water jacket gasket. This part is intended for technicians and boat owners performing water jacket maintenance, cylinder head service, or general cooling system repair on compatible Yamaha outboard engines. Installing a quality replacement gasket like the 18-0779 helps restore proper sealing after disassembly for maintenance or repair work.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0779\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Water Jacket Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity Required Per Engine:\u003c\/strong\u003e 2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.24 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 6G5-11193-A0-00\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eYamaha outboard engines\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e6G5-11193-A0-00\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0779 water jacket gasket fit?\u003c\/strong\u003e The Sierra 18-0779 is designed for Yamaha outboard engines, sealing the water jacket area of the powerhead.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does 18-0779 replace?\u003c\/strong\u003e It is a direct interchange for Yamaha part number 6G5-11193-A0-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets do I need for one engine?\u003c\/strong\u003e Each engine application requires 2 of the 18-0779 gaskets, so plan to order enough to cover that quantity.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0779 sold as a single gasket or a set?\u003c\/strong\u003e The 18-0779 is sold as a single water jacket gasket per package, not as part of a multi-piece kit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-0779 gasket?\u003c\/strong\u003e This water jacket gasket is white in color.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0779 gasket weigh?\u003c\/strong\u003e The Sierra 18-0779 weighs 0.24 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-0779 a genuine OEM part or aftermarket?\u003c\/strong\u003e The 18-0779 is a Sierra-manufactured replacement gasket built to meet or exceed the quality of the original Yamaha 6G5-11193-A0-00 equipment it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen would I need to replace the water jacket gasket on a Yamaha outboard?\u003c\/strong\u003e The 18-0779 water jacket gasket should be replaced any time the powerhead is disassembled for service or if the original gasket has failed and is causing a coolant leak or overheating.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0779 come with installation instructions?\u003c\/strong\u003e The Sierra 18-0779 is a gasket component intended for installation by someone familiar with Yamaha outboard powerhead service; it does not include a separate instruction sheet.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-0779 be used on other engine brands besides Yamaha?\u003c\/strong\u003e The 18-0779 is designed specifically for Yamaha outboard engines using the 6G5-11193-A0-00 water jacket gasket.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988085682395,"sku":"SIE-18-0779","price":21.73,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0779_lg__94038.1558119789.500.750.jpg?v=1785188314"},{"product_id":"sierra-18-0868-marine-intake-manifold-gasket-set-pkg-of-2-replaces-omc-3854269-mercury-27-17145-fits-gm-v-8-305-350-cid-mercruiser-omc-5-7l","title":"Sierra 18-0868 Intake Manifold Gasket Set, Replaces 16.50-00232, Fits MCM\/MIE GM V-8 305 \u0026 350 cid Engines","description":"\u003cp\u003eThe Sierra 18-0868 intake manifold gasket set seals the intake manifold to the engine block on compatible marine engines, providing the gasket surface needed to prevent coolant, oil, or combustion leaks at this joint. It is sold as a package of 2 gaskets, giving a complete matched set for a single intake manifold installation or reseal job. The set is built as a direct replacement for OEM part number 16.50-00232, so it installs in place of the original equipment gasket without modification.\u003c\/p\u003e\u003cp\u003eThis gasket set is designed for MCM\/MIE GM V-8 engines in 305 and 350 cubic inch displacement, 1975 and newer, and also fits OMC 5.7L engines from the 1994 and 1996-1997 model years. Boat owners and marine technicians use it during intake manifold removal, engine rebuilds, or when addressing a leaking or failed intake gasket. Confirming your engine matches the GM V-8 305\/350 cid or OMC 5.7L applications listed, or cross-referencing to OEM 16.50-00232, is the best way to verify fit before ordering.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0868\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Intake Manifold Gasket Set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Package of 2 gaskets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.31 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999755131\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 16.50-00232\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMCM\/MIE GM V-8 305 and 350 cid engines, 1975 and newer\u003c\/li\u003e\n\u003cli\u003eOMC 5.7L engines, 1994, 1996-1997\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e16.50-00232\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the Sierra 18-0868 gasket set replace?\u003c\/strong\u003e The Sierra 18-0868 intake manifold gasket set replaces OEM number 16.50-00232.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets are included in the 18-0868 set?\u003c\/strong\u003e This set is sold as a package of 2 gaskets, providing a complete matched pair for an intake manifold installation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich engines does the Sierra 18-0868 gasket set fit?\u003c\/strong\u003e It fits MCM\/MIE GM V-8 engines in 305 and 350 cubic inch displacement (1975 and newer), as well as OMC 5.7L engines from 1994 and 1996-1997.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this gasket set fit an OMC 5.7L engine?\u003c\/strong\u003e Yes, the 18-0868 set is designed to fit OMC 5.7L engines from the 1994 and 1996-1997 model years.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0868 fit MerCruiser MCM\/MIE engines?\u003c\/strong\u003e Yes, it fits MCM\/MIE GM V-8 305 and 350 cid engines built in 1975 and newer.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0868 gasket set weigh?\u003c\/strong\u003e The 18-0868 intake manifold gasket set weighs 0.31 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0868 gasket set?\u003c\/strong\u003e The set measures 0.39 x 0.39 x 0.39 inches as packaged.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0868 an OEM part or an aftermarket replacement?\u003c\/strong\u003e It is an aftermarket gasket set manufactured by Sierra, engineered as a direct replacement for OEM 16.50-00232.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-0868 gasket set?\u003c\/strong\u003e You receive a package of 2 intake manifold gaskets, the complete set needed for one intake manifold installation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I confirm the 18-0868 is the correct gasket for my engine?\u003c\/strong\u003e Match your engine to MCM\/MIE GM V-8 305 or 350 cid (1975 and newer) or OMC 5.7L (1994, 1996-1997), or cross-reference to OEM number 16.50-00232.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988085813467,"sku":"SIE-18-0868","price":31.38,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0868_lg__64758.1558119292.500.750.jpg?v=1785188366"},{"product_id":"sierra-18-0826-exhaust-cover-gasket-for-yamaha-outboards-replaces-oem-688-41112-a0-00","title":"Sierra 18-0826 Drain Screw Gasket, OEM 90430-14115-00-00, Yamaha Outboard","description":"\u003cp\u003eThe Sierra 18-0826 is a drain screw gasket engineered as a direct replacement for Yamaha outboard motors, sealing the drain screw to prevent oil or fluid seepage at the drain point. It is built from aluminum construction and finished in red, matching the original equipment appearance for a clean, factory-correct look on reinstallation. This is a small but critical sealing component: a worn or reused drain screw gasket is a common source of slow oil weeps around the drain plug, so replacing it whenever the drain screw is removed for a service interval helps maintain a proper seal and keeps the powerhead free of leaks.\u003c\/p\u003e\u003cp\u003eSierra manufactures the 18-0826 to match the Yamaha OEM specification 90430-14115-00-00, so it installs the same way as the original gasket with no modification required. It ships as a single gasket (package quantity of 1) sized to fit the drain screw location on covered Yamaha outboard engines. Given its light weight and compact size, it is typically kept on hand as a routine maintenance part alongside other gaskets replaced during oil changes or lower-unit service.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0826\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Drain Screw Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Aluminum\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Red\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 1 inch x 1 inch x 0.3 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Type:\u003c\/strong\u003e 4 Stroke\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuel Type:\u003c\/strong\u003e Gasoline\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874757\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 90430-14115-00-00\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits Yamaha outboard motors using drain screw gasket 90430-14115-00-00.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e90430-14115-00-00\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0826 fit?\u003c\/strong\u003e The Sierra 18-0826 drain screw gasket is designed for Yamaha outboard motors and is a direct match for OEM part 90430-14115-00-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0826 the same as the Yamaha OEM gasket?\u003c\/strong\u003e Yes, the Sierra 18-0826 is manufactured to the same specification as Yamaha OEM number 90430-14115-00-00 and installs the same way.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the drain screw gasket made from?\u003c\/strong\u003e It is made from aluminum, finished in red to match the original Yamaha appearance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in a package?\u003c\/strong\u003e The Sierra 18-0826 ships as a single gasket, with a package quantity of 1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0826?\u003c\/strong\u003e Packaged dimensions are 1 inch by 1 inch by 0.3 inch, reflecting the small size typical of a drain screw gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0826 weigh?\u003c\/strong\u003e The Sierra 18-0826 weighs 0.01 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace this gasket?\u003c\/strong\u003e This drain screw gasket should be replaced any time the drain screw is removed, such as during an oil change or lower-unit service, since a reused gasket is a common source of slow leaks around the drain plug.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0826 an aftermarket or genuine part?\u003c\/strong\u003e The 18-0826 is a Sierra-manufactured gasket built to match the Yamaha OEM specification 90430-14115-00-00, rather than a Yamaha-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engine type is this gasket used with?\u003c\/strong\u003e The Sierra 18-0826 drain screw gasket is used on 4 stroke gasoline outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the color of the gasket matter for fit?\u003c\/strong\u003e No, the red finish on the Sierra 18-0826 is a cosmetic match to the original equipment and does not affect the seal or fit.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988085879003,"sku":"SIE-18-0826","price":1.77,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0826_lg__06664.1711979440.500.750.jpg?v=1785188749"},{"product_id":"sierra-18-0879-adapter-plate-gasket-for-mercury-outboards-replaces-oem-27-38501-1","title":"Sierra 18-0879 Adapter Plate Gasket, Replaces Mercury 27-30501-1","description":"\u003cp\u003eThe Sierra 18-0879 Adapter Plate Gasket is a replacement gasket engineered to meet or exceed original equipment quality for Mercury outboard applications. It seals the adapter plate to prevent leaks and maintain proper compression at the mating surface, restoring a tight seal when the original gasket has hardened, torn, or lost its seal after removal for service. As a direct cross-reference to Mercury part number 27-30501-1, it is sized and shaped to install as a drop-in replacement without modification.\u003c\/p\u003e\u003cp\u003eThis gasket is a single-use component, meaning a new one should be installed any time the adapter plate is removed for maintenance or repair, since reusing a compressed gasket can result in leaks. It ships as a single gasket and is intended for buyers who already know they need this specific Sierra part number or its Mercury OEM equivalent.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0879\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Adapter Plate Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercury Outboard Gaskets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity per Application:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999751621\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGTIN:\u003c\/strong\u003e 00030999751621\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 27-30501-1\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits applications specified by Mercury OEM part number 27-30501-1.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-30501-1\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0879 Adapter Plate Gasket fit?\u003c\/strong\u003e The Sierra 18-0879 Adapter Plate Gasket is designed as a replacement for Mercury OEM part number 27-30501-1, so it fits the same adapter plate applications that number covers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0879 the same as Mercury 27-30501-1?\u003c\/strong\u003e Yes, Sierra part number 18-0879 is the direct cross-reference to Mercury OEM number 27-30501-1, made to meet or exceed the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in one package?\u003c\/strong\u003e One Sierra 18-0879 Adapter Plate Gasket ships per package, matching the quantity of one used per adapter plate application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0879 gasket weigh?\u003c\/strong\u003e The Sierra 18-0879 Adapter Plate Gasket weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the adapter plate gasket be reused after removal?\u003c\/strong\u003e No, a gasket like the Sierra 18-0879 should be replaced with a new one any time the adapter plate is removed, since a used gasket has already been compressed and may no longer seal properly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part or aftermarket?\u003c\/strong\u003e The 18-0879 is a Sierra-branded gasket built to meet or exceed the quality of the original equipment part it replaces, identified by the OEM cross-reference 27-30501-1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of product is the 18-0879 gasket used in?\u003c\/strong\u003e Sierra 18-0879 is listed under Mercury Outboard Gaskets, used to seal the adapter plate on applicable Mercury outboard components.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0879 gasket require any modification to install?\u003c\/strong\u003e No, the Sierra 18-0879 Adapter Plate Gasket is made as a direct replacement for Mercury 27-30501-1 and installs in place of the original without modification.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when ordering the 18-0879 gasket?\u003c\/strong\u003e Ordering the Sierra 18-0879 includes one Adapter Plate Gasket only.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace the adapter plate gasket?\u003c\/strong\u003e An adapter plate gasket like the Sierra 18-0879 typically needs replacement after the plate is removed for service, or if the original gasket has failed and is allowing a leak at the adapter plate seal.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988086108379,"sku":"SIE-18-0879","price":7.66,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0879_lg__38733.1558120552.500.750.jpg?v=1785188650"},{"product_id":"timing-cover-gasket-18-0887-for-volvo-penta-marine-engines-cam-gear-cover-gasket","title":"Sierra 18-0887 Timing Cover Gasket for GM 4.3L, 5.0L \u0026 5.7L Engines, Replaces 3852654, 3853512","description":"\u003cp\u003eThe Sierra 18-0887 Timing Cover Gasket seals the timing cover against the engine block on GM 4.3L, 5.0L, and 5.7L marine engines, preventing oil leaks at this critical junction. It is a direct-fit replacement gasket designed to restore a proper seal when the original gasket has hardened, cracked, or begun leaking from age and heat cycling. Installing a fresh timing cover gasket during a timing cover removal, timing chain service, or general engine reseal helps ensure the cover seats correctly and holds oil pressure without seepage.\u003c\/p\u003e\u003cp\u003eThis gasket is manufactured to match the mounting pattern and sealing surface of the OEM GM timing cover gasket, cross-referencing directly to OEM part numbers 3852654 and 3853512. Because it is a precise fit replacement, no modification to the timing cover or engine block is required during installation. Boat owners and marine mechanics use it as a maintenance part whenever the timing cover is removed for inspection, repair, or replacement of related timing components.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0887\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Timing Cover Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Compatibility:\u003c\/strong\u003e GM 4.3L, 5.0L \u0026amp; 5.7L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e 3852654, 3853512\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGM 4.3L engines\u003c\/li\u003e\n\u003cli\u003eGM 5.0L engines\u003c\/li\u003e\n\u003cli\u003eGM 5.7L engines\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e3852654\u003c\/li\u003e\n\u003cli\u003e3853512\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0887 timing cover gasket fit?\u003c\/strong\u003e The Sierra 18-0887 timing cover gasket fits GM 4.3L, 5.0L, and 5.7L marine engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does this gasket replace?\u003c\/strong\u003e Sierra 18-0887 replaces OEM GM part numbers 3852654 and 3853512.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0887 a direct OEM replacement?\u003c\/strong\u003e Yes, the Sierra 18-0887 is a direct cross-reference replacement for OEM timing cover gaskets 3852654 and 3853512, so no modification is needed for installation on compatible GM engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the timing cover gasket weigh?\u003c\/strong\u003e The Sierra 18-0887 timing cover gasket weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should this gasket be replaced?\u003c\/strong\u003e This gasket should be replaced any time the timing cover is removed from a GM 4.3L, 5.0L, or 5.7L marine engine, such as during timing chain service or if the original gasket is leaking oil.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan this gasket be reused after removing the timing cover?\u003c\/strong\u003e No, a timing cover gasket like the Sierra 18-0887 should be replaced with a new one any time the timing cover is removed, since reusing a compressed gasket can result in oil leaks.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0887 fit both carbureted and fuel-injected GM 4.3L, 5.0L, and 5.7L engines?\u003c\/strong\u003e The Sierra 18-0887 is listed as fitting GM 4.3L, 5.0L, and 5.7L engines generally, based on displacement rather than fuel delivery type.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat brand is part number 18-0887?\u003c\/strong\u003e Part number 18-0887 is manufactured by Sierra.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this gasket seal correctly without additional sealant?\u003c\/strong\u003e The Sierra 18-0887 is designed to match the OEM sealing surface and pattern of gaskets 3852654 and 3853512 for proper sealing when installed per standard timing cover installation procedures.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0887 gasket sold individually?\u003c\/strong\u003e The Sierra 18-0887 timing cover gasket is a single gasket part matched to GM 4.3L, 5.0L, and 5.7L timing covers.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988086141147,"sku":"SIE-18-0887","price":4.73,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0887_lg_1__71421.1558121132.500.750.jpg?v=1785329144"},{"product_id":"sierra-18-0907-oil-drain-plug-gasket-set-for-volvo-penta-200-250-270-270t-275-275a","title":"Sierra 18-0907 Gasket Set - Oil Plug Gaskets for Volvo 200, 250, 270, 270T, 275, 275A","description":"\u003cp\u003eThe Sierra 18-0907 is a gasket set engineered for oil plug applications on Volvo 200, 250, 270, 270T, 275, and 275A engines. Each gasket in the set is built from high-grade sealing material to Sierra's manufacturing standards, giving boat owners a reliable replacement for worn or hardened factory gaskets that can lead to oil seepage around the plug. Using updated manufacturing technology and design processes, Sierra produces these gaskets to match original equipment fitment and sealing performance, so installation follows the same steps as removing and replacing the factory gasket.\u003c\/p\u003e\u003cp\u003eThis set is a straightforward maintenance item for anyone servicing the oil plug on a compatible Volvo engine, whether during a routine oil change, a gasket refresh, or a broader engine service. Because the gasket is designed for O.E. Fitment, it seats correctly without modification and provides a dependable seal once torqued to the plug's specification. Sierra backs its parts, including this gasket set, with its standard customer satisfaction warranty.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0907\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Components:\u003c\/strong\u003e Gasket Set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Items:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Oil Plugs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282188504\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eVolvo 200, 250, 270, 270T, 275 \u0026amp; 275A\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0907 gasket set fit?\u003c\/strong\u003e It fits Volvo 200, 250, 270, 270T, 275, and 275A engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-0907 used for?\u003c\/strong\u003e This gasket set is designed for oil plugs, sealing the oil plug against leaks on compatible Volvo engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in the 18-0907 set?\u003c\/strong\u003e The set ships as one item, listed as a single gasket set (Number of Items: 1).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0907 gasket set weigh?\u003c\/strong\u003e It weighs 0.01 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0907 an OEM or aftermarket part?\u003c\/strong\u003e The 18-0907 is a Sierra-manufactured gasket set built for O.E. Fitment, sold as an aftermarket replacement rather than a Volvo-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-0907 gasket made from?\u003c\/strong\u003e Sierra manufactures the 18-0907 using high-grade gasket and sealing materials intended for durability and reliable sealing performance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0907 come with a warranty?\u003c\/strong\u003e Yes, the 18-0907 gasket set is covered under Sierra's standard customer satisfaction warranty.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the 18-0907 gasket set for a routine oil change?\u003c\/strong\u003e Yes, this gasket set is intended for oil plug service, making it suitable for use during an oil change on a compatible Volvo engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0907 gasket set?\u003c\/strong\u003e The UPC for this gasket set is 808282188504.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the 18-0907 gasket seal properly without modification?\u003c\/strong\u003e Yes, the gasket is designed for O.E. Fitment on the listed Volvo engines, so it installs and seals in place of the original oil plug gasket without modification.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988086173915,"sku":"SIE-18-0907","price":10.82,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0907_lg__52059.1558118796.500.750.jpg?v=1785189119"},{"product_id":"air-silencer-gasket-oem-314115-for-johnson-evinrude-outboards-sierra-18-0933","title":"Sierra 18-0933 Air Silencer Gasket, Replaces 314115, for Johnson\/Evinrude Outboard Motors","description":"\u003cp\u003eThe Sierra 18-0933 Air Silencer Gasket is a round replacement gasket engineered to seal the air silencer to the carburetor intake on Johnson\/Evinrude outboard motors. It is built to meet or exceed original equipment quality, giving it the fit and sealing performance of the factory gasket it replaces. This gasket restores a proper air-tight seal at the air silencer mounting point, which is essential for correct carburetor airflow and preventing intake leaks that can cause rough running or hard starting.\u003c\/p\u003e\u003cp\u003eAs a low-cost, frequently replaced maintenance part, the 18-0933 is typically installed whenever the air silencer is removed for carburetor service, cleaning, or general outboard maintenance. Its round shape and OEM-equivalent construction make it a direct swap for the original Johnson\/Evinrude gasket, and it is sold individually for a single air silencer location.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-0933\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Evinrude Outboard Gasket Sets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.1 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999755414\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible With:\u003c\/strong\u003e Johnson\/Evinrude Outboard Motor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e 314115\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eJohnson\/Evinrude Outboard Motor (air silencer to carburetor location)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e314115\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0933 gasket fit?\u003c\/strong\u003e The Sierra 18-0933 Air Silencer Gasket is designed for Johnson\/Evinrude outboard motors, sealing the air silencer to the carburetor intake.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the 18-0933 replace?\u003c\/strong\u003e It replaces OEM number 314115, so any listing that references 314115 for a Johnson\/Evinrude air silencer gasket corresponds to the Sierra 18-0933.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0933 an OEM-equivalent gasket?\u003c\/strong\u003e Yes, the 18-0933 is built to meet or exceed original equipment quality, making it a direct equivalent to the factory Johnson\/Evinrude air silencer gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape is the 18-0933 gasket?\u003c\/strong\u003e The 18-0933 Air Silencer Gasket is round in shape, matching the mounting flange of the air silencer it seals.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0933 gasket weigh?\u003c\/strong\u003e The Sierra 18-0933 weighs 0.1 pounds, consistent with its use as a thin sealing gasket rather than a structural component.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the air silencer gasket?\u003c\/strong\u003e Replace the 18-0933 any time the air silencer is removed for carburetor cleaning or service, since gaskets should not be reused once broken loose from their seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-0933?\u003c\/strong\u003e Each order includes one Sierra 18-0933 Air Silencer Gasket for a single air silencer location on a Johnson\/Evinrude outboard motor.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the UPC 030999755414 match the Sierra 18-0933?\u003c\/strong\u003e Yes, UPC 030999755414 is the identifier for the Sierra 18-0933 Air Silencer Gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I install the 18-0933 myself?\u003c\/strong\u003e Yes, the 18-0933 is a straightforward drop-in gasket that installs at the air silencer to carburetor joint during routine outboard maintenance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0933 a genuine Sierra part or aftermarket?\u003c\/strong\u003e The 18-0933 is a genuine Sierra part manufactured to meet or exceed original equipment specifications for Johnson\/Evinrude outboard motors.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988086403291,"sku":"SIE-18-0933","price":4.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0933_lg__93983.1558120209.500.750.jpg?v=1785188793"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/collections\/ECO-96009__17545.1747363868.500.750.jpg?v=1785359957","url":"https:\/\/www.goodvibesmarina.com\/collections\/gvcat-engine-parts-systems-gaskets-seals-bearings.oembed?page=6","provider":"Good Vibes Marina","version":"1.0","type":"link"}