{"product_id":"sierra-18-2864-9-powerhead-base-gasket-pack-of-2-replaces-oem-330621-johnson-evinrude-25-35-hp-outboards","title":"Sierra 18-2864-9 Powerhead Base Gasket, Replaces 321727, Fits Johnson\/Evinrude V-4 25\/35 HP Outboards, Pack of 2","description":"\u003cp\u003eThe Sierra 18-2864-9 is a powerhead base gasket sold as a pack of two, designed to seal the base of the powerhead on Johnson and Evinrude V-4 outboard engines rated 25\/35 HP. This gasket sits between the powerhead and the engine block, forming the critical seal that keeps combustion pressure, oil, and coolant properly contained during operation. A worn, cracked, or compressed base gasket is a common source of oil seepage, loss of compression, or overheating on these outboards, and replacing it with the correct Sierra part restores the factory seal.\u003c\/p\u003e\u003cp\u003eSierra manufactures this gasket to meet or exceed the specifications of the original equipment part it replaces, giving it a reliable fit and consistent sealing performance without modification to surrounding components. Because it ships two to a package, buyers performing a full powerhead service have enough material on hand without needing a second order, and the pack covers engines that use two gaskets per rebuild or a spare for a future 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 18-2864-9\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 per pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e Johnson\/Evinrude V-4 outboards, 25\/35 HP\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.12 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplaces (OEM):\u003c\/strong\u003e 321727\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eJohnson\/Evinrude V-4 outboards, 25\/35 HP\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e321727\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-2864-9 powerhead base gasket fit?\u003c\/strong\u003e This gasket fits Johnson and Evinrude V-4 outboard engines rated 25\/35 HP.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in a pack?\u003c\/strong\u003e The 18-2864-9 is sold as a pack of two powerhead base gaskets.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-2864-9 replace an OEM Johnson\/Evinrude part number?\u003c\/strong\u003e Yes, it replaces OEM part number 321727.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2864-9 gasket genuine OEM or aftermarket?\u003c\/strong\u003e It is an aftermarket Sierra replacement gasket, manufactured to meet or exceed the specifications of the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the powerhead base gasket weigh?\u003c\/strong\u003e The 18-2864-9 pack weighs 0.12 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is a powerhead base gasket used for?\u003c\/strong\u003e A powerhead base gasket seals the joint between the outboard powerhead and the engine block, containing combustion pressure, oil, and coolant so the engine runs without leaks or loss of compression.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill I need one or two of these gaskets for a single engine rebuild?\u003c\/strong\u003e Since the 18-2864-9 ships two per pack, one package supplies both gaskets typically needed for a Johnson\/Evinrude V-4 powerhead service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat signs indicate the powerhead base gasket needs replacing?\u003c\/strong\u003e Oil seepage at the base of the powerhead, loss of compression, or overheating on a Johnson\/Evinrude V-4 25\/35 HP outboard are common signs the 18-2864-9 gasket needs replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs installation of the 18-2864-9 gasket something a DIY mechanic can do?\u003c\/strong\u003e Replacing a powerhead base gasket requires removing the powerhead from the engine block, so it is a more involved job typically done during a full teardown or rebuild rather than a quick DIY swap.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-2864-9 come with a warranty?\u003c\/strong\u003e Yes, this Sierra powerhead base gasket is covered under Sierra's standard customer satisfaction warranty.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988132081883,"sku":"SIE-18-2864-9","price":26.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-2864-9__73844.1737827435.500.750.jpg?v=1785188912","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-2864-9-powerhead-base-gasket-pack-of-2-replaces-oem-330621-johnson-evinrude-25-35-hp-outboards","provider":"Good Vibes Marina","version":"1.0","type":"link"}