{"product_id":"sierra-18-3074-water-pump-impeller-for-yamaha-outboards-6-fin-neoprene-replaces-mercury-47-84027m-and-yamaha-682-44352-01-00","title":"Sierra 18-3074 Neoprene Impeller, 6-Fin, for Yamaha Outboard Motor, Replaces 47-84027M","description":"\u003cp\u003eThe Sierra 18-3074 is a neoprene water pump impeller built for Yamaha outboard motors. As the impeller inside the water pump housing, it is the component responsible for pulling raw water through the lower unit and pushing it up to cool the powerhead; a worn, cracked, or missing fin on the impeller is one of the most common causes of overheating in an outboard. The Sierra 18-3074 features 6 fins molded in durable neoprene rubber, a material chosen for its flexibility and resistance to heat and wear as it spins against the pump housing wall. Sierra manufactures this impeller to meet or exceed the quality of the original equipment part it replaces, so it installs the same way and delivers the same water flow as the OEM component. This impeller is intended for use on Yamaha outboard motors and is also cross-referenced to equivalent parts from GLM, Mallory, and Mercury Marine, making it a straightforward replacement whether the original impeller was a Yamaha, Mercury, or other branded part. Because water pump impellers are fit-specific, buyers should confirm the existing part number on their pump before ordering to ensure proper fit. Routine impeller replacement, typically as part of scheduled water pump maintenance, helps prevent overheating damage and keeps the cooling system operating as designed.\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 18-3074\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Water Pump Impeller\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Neoprene\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Fins:\u003c\/strong\u003e 6\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 impeller per package\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 030999315267\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 47-84027M\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e Yamaha outboard motor\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for Yamaha outboard motors. Confirm the existing impeller part number on your water pump before ordering to ensure proper fit.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cp\u003e47-84027M\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-3074 impeller fit?\u003c\/strong\u003e The Sierra 18-3074 is designed for Yamaha outboard motors. Since water pump impellers are fit-specific, confirm the part number on your current impeller before ordering to make sure the 18-3074 matches your pump.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the Sierra 18-3074 replace?\u003c\/strong\u003e It replaces OEM part number 47-84027M. Buyers can order the Sierra 18-3074 as a direct equivalent to that original Mercury Marine part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many fins does this impeller have?\u003c\/strong\u003e 6 fins, molded in neoprene rubber. The fin count and material match the design of the original equipment impeller it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the Sierra 18-3074 impeller made from?\u003c\/strong\u003e Neoprene rubber. This material is used because it flexes without cracking under the friction and heat generated inside a running water pump housing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-3074 weigh?\u003c\/strong\u003e The impeller weighs 0.01 pounds, consistent with a small single-component water pump part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3074 a genuine Yamaha part or an aftermarket part?\u003c\/strong\u003e The 18-3074 is a Sierra-manufactured impeller, not a Yamaha-branded part. Sierra builds it to meet or exceed the quality of the original equipment impeller it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many impellers come in one Sierra 18-3074 package?\u003c\/strong\u003e One impeller ships per package under part number 18-3074, ready to install as a direct replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-3074 impeller?\u003c\/strong\u003e It is white, which is the standard color Sierra uses for the neoprene compound in this impeller.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should I replace the impeller on my Yamaha outboard?\u003c\/strong\u003e An impeller like the Sierra 18-3074 should be replaced any time it shows cracked, torn, or missing fins, or as part of routine water pump service, since worn fins reduce raw water flow and can lead to overheating.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the Sierra 18-3074?\u003c\/strong\u003e The order includes one Sierra 18-3074 neoprene impeller. It does not include the wear plate gasket or woodruff key, which are separate parts in the water pump kit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the Sierra 18-3074 fit a Mercury outboard as well?\u003c\/strong\u003e The Sierra 18-3074 is built for Yamaha outboard motors, but it is manufactured as an equivalent to OEM part 47-84027M, so it is compatible with equipment that originally used that part number. Always verify against your existing part number before ordering.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988138766555,"sku":"SIE-18-3074","price":23.81,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-3074_lg__84982.1558125145.500.750.jpg?v=1785188283","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-3074-water-pump-impeller-for-yamaha-outboards-6-fin-neoprene-replaces-mercury-47-84027m-and-yamaha-682-44352-01-00","provider":"Good Vibes Marina","version":"1.0","type":"link"}