{"product_id":"679-w0078-a0-water-pump-impeller-kit-for-yamaha-omc-c40-235-240","title":"679-W0078-A0 Water Pump Impeller Kit for Yamaha OMC C40 235 240 | JLM Marine","description":"\u003ch2\u003eWater Pump Impeller Kit – Fits Yamaha 2-Stroke 40 HP C40 \u0026amp; OMC Cobra Stern Drive 235\/240\u003c\/h2\u003e\n\n\u003cp\u003eThis water pump impeller kit is engineered for \u003cstrong\u003eYamaha 2-Stroke 40 HP C40 outboards (1990–1997)\u003c\/strong\u003e and \u003cstrong\u003eOMC Cobra Stern Drive models 235 (1971, 1975–1977) and 240 (1978)\u003c\/strong\u003e. It provides a direct replacement solution for critical cooling system components, ensuring reliable water flow and consistent engine temperature regulation.\u003c\/p\u003e\n\n\u003cp\u003eThis kit directly replaces Yamaha part numbers \u003cstrong\u003e6F5-44352-00, 6F5-44352-A0, 679-W0078-00, 679-W0078-A0\u003c\/strong\u003e and Sierra Marine \u003cstrong\u003e18-3374, 18-3397, 18-3398\u003c\/strong\u003e. All components are designed to meet OEM specifications for precise fitment and performance.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eComplete kit includes impeller, key, gaskets, and seal for a comprehensive rebuild\u003c\/li\u003e\n  \u003cli\u003eCompatible with both Yamaha outboard and OMC stern drive applications\u003c\/li\u003e\n  \u003cli\u003eDesigned for saltwater and freshwater cooling systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Cross-Reference\u003c\/h2\u003e\n\n\u003cp\u003eUse this table to confirm equivalent part numbers across OEM and aftermarket brands.\u003c\/p\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eBrand\u003c\/th\u003e\n      \u003cth\u003ePart Number\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e6F5-44352-00\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e6F5-44352-A0\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e679-W0078-00\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e679-W0078-A0\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSierra Marine\u003c\/td\u003e\n      \u003ctd\u003e18-3374\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSierra Marine\u003c\/td\u003e\n      \u003ctd\u003e18-3397\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSierra Marine\u003c\/td\u003e\n      \u003ctd\u003e18-3398\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eCompatible Engine Models\u003c\/h2\u003e\n\n\u003cp\u003eConfirm your engine model\/year in the table below. For Yamaha owners, here's a guide to help you identify your engine's serial\/model: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/serial-number-guide\/yamaha-outboard-serial-number-guide-2025\" rel=\"nofollow noopener\" target=\"_blank\"\u003eYamaha Serial Number Guide\u003c\/a\u003e. You can also review exploded diagrams to verify part numbers: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/serial-number-guide\/yamaha-outboard-parts-diagrams-catalog\" rel=\"nofollow noopener\" target=\"_blank\"\u003eYamaha Parts Diagrams \u0026amp; Catalog\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n  \u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eYears\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eC40\u003c\/td\u003e\n        \u003ctd\u003e40 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1990–1991\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eC40\u003c\/td\u003e\n        \u003ctd\u003e40 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1992–1997\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eOMC Cobra Stern Drive\u003c\/td\u003e\n        \u003ctd\u003e235\u003c\/td\u003e\n        \u003ctd\u003e235\u003c\/td\u003e\n        \u003ctd\u003e-\u003c\/td\u003e\n        \u003ctd\u003e1971\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eOMC Cobra Stern Drive\u003c\/td\u003e\n        \u003ctd\u003e235\u003c\/td\u003e\n        \u003ctd\u003e235\u003c\/td\u003e\n        \u003ctd\u003e-\u003c\/td\u003e\n        \u003ctd\u003e1975–1977\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eOMC Cobra Stern Drive\u003c\/td\u003e\n        \u003ctd\u003e240\u003c\/td\u003e\n        \u003ctd\u003e240\u003c\/td\u003e\n        \u003ctd\u003e-\u003c\/td\u003e\n        \u003ctd\u003e1978\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eSpecification\u003c\/th\u003e\n      \u003cth\u003eValue\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eOEM Number\u003c\/td\u003e\n      \u003ctd\u003e679-W0078-A0\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eApplication\u003c\/td\u003e\n      \u003ctd\u003eWater Pump Rebuild\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eCompatible Brands\u003c\/td\u003e\n      \u003ctd\u003eYamaha, OMC\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eKit Type\u003c\/td\u003e\n      \u003ctd\u003eComplete Impeller Kit\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\n\u003cp\u003eThis complete water pump impeller kit includes the following components:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cspan style=\"color:red;\"\u003e1 × Water Pump Impeller\u003c\/span\u003e (6F5-44352-00, 676-44352-00)\u003c\/li\u003e\n  \u003cli\u003e1 × Key, Impeller (90280-04M00-00)\u003c\/li\u003e\n  \u003cli\u003e1 × Gasket, Water Pump (676-44315-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 × Gasket, Water Pump (676-44324-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 × Gasket, Water Pump (679-44316-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 × Seal, Water (663-44366-00-00)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\n\u003col\u003e\n  \u003cli\u003eDisconnect the fuel line and remove the lower unit from the outboard or stern drive following manufacturer service manual procedures.\u003c\/li\u003e\n  \u003cli\u003eRemove the water pump housing cover and old impeller. Inspect the housing for wear, scoring, or corrosion.\u003c\/li\u003e\n  \u003cli\u003eClean all gasket surfaces thoroughly using a gasket scraper and solvent to ensure a proper seal.\u003c\/li\u003e\n  \u003cli\u003eInstall the new impeller key into the driveshaft slot, ensuring it is seated firmly.\u003c\/li\u003e\n  \u003cli\u003eLubricate the new impeller with marine-grade grease or glycerin. Insert it onto the driveshaft, aligning the key slot.\u003c\/li\u003e\n  \u003cli\u003eRotate the impeller blades in the direction of normal rotation to ensure they are correctly oriented.\u003c\/li\u003e\n  \u003cli\u003eInstall the new gaskets in the correct order as specified in your service manual, applying a thin layer of marine sealant if recommended.\u003c\/li\u003e\n  \u003cli\u003eReinstall the water pump housing, ensuring all fasteners are tightened to the manufacturer's specified torque values.\u003c\/li\u003e\n  \u003cli\u003eReattach the lower unit to the outboard or stern drive, reconnect the fuel line, and check for proper alignment.\u003c\/li\u003e\n  \u003cli\u003eSubmerge the lower unit in water or connect a flushing device. Start the engine and verify strong water flow from the cooling system tell-tale.\u003c\/li\u003e\n  \u003cli\u003eAllow the engine to reach operating temperature and inspect all seals and gaskets for leaks.\u003c\/li\u003e\n  \u003cli\u003eIf leaks or weak water flow are detected, shut down immediately and re-inspect the installation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How do I confirm this impeller kit fits my engine?\u003c\/strong\u003e\u003cbr\u003e\nA: Verify your engine model and year against the compatibility table above. Cross-reference your existing part numbers (found on the old impeller or in your service manual) with the part number cross-reference table to confirm fitment.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How often should I replace the water pump impeller?\u003c\/strong\u003e\u003cbr\u003e\nA: Most manufacturers recommend replacing the impeller every 2–3 years or 200–300 hours of operation, whichever comes first. If you operate in sandy or debris-filled water, inspect and replace more frequently.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What are the signs of a failing water pump impeller?\u003c\/strong\u003e\u003cbr\u003e\nA: Common symptoms include weak or no water flow from the tell-tale, engine overheating, reduced power, steam from the engine, or visible impeller damage such as cracked, broken, or glazed blades.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Can I reuse the old gaskets and seals?\u003c\/strong\u003e\u003cbr\u003e\nA: No. Always replace all gaskets and seals during a water pump rebuild to prevent leaks and ensure proper cooling system pressure and performance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What is the difference between OEM and aftermarket impeller kits?\u003c\/strong\u003e\u003cbr\u003e\nA: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How fast do you ship and how much does it cost?\u003c\/strong\u003e\u003cbr\u003e\nA: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What is your warranty and return policy?\u003c\/strong\u003e\u003cbr\u003e\nA: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused \u0026amp; in original condition); please see our policy page or reach out for instructions.\u003c\/p\u003e\n\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003eVerify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.\u003c\/li\u003e\n  \u003cli\u003eThis product is an aftermarket replacement part and is not an OEM component.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended to ensure safety and optimal performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy Choose JLM MARINE?\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQuality Assured:\u003c\/strong\u003e As a trusted manufacturer for over 20 years, we supply top marine brands globally.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFast Global Shipping:\u003c\/strong\u003e Free delivery worldwide in 5–15 days.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDirect from Manufacturer:\u003c\/strong\u003e Competitive pricing without compromising quality.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"JLM Marine","offers":[{"title":"Default Title","offer_id":50476214124857,"sku":"23KY090","price":20.42,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0885\/0433\/6697\/files\/Water_Pump_Impeller_Kit_for_Yamaha_40HP_6F5-W0078-A0_-_JLM_MARINE-8289065.jpg?v=1754991486","url":"https:\/\/jlmmarine.com\/products\/679-w0078-a0-water-pump-impeller-kit-for-yamaha-omc-c40-235-240","provider":"JLM Marine Boat Parts Limited","version":"1.0","type":"link"}