{"product_id":"water-pump-impeller-kit-fits-yamaha-mariner-20-30-hp-replaces-689-w0078-a6-a4-18-3426-3427","title":"Water Pump Impeller Kit – Fits Yamaha \u0026 Mariner 20-30 HP (Replaces 689-W0078-A6\/A4, 18-3426\/3427)","description":"\u003cstyle\u003e\n  \/* Outer container allows horizontal scrolling (with iOS momentum) *\/\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n\n  \/* Base table styles *\/\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n\n  \/* Key: prevent wrapping, word breaks, and vertical text in headers *\/\n  table.ss-table th {\n    white-space:nowrap;       \/* Do not wrap *\/\n    word-break:normal;        \/* Don’t break words *\/\n    letter-spacing:normal;    \/* Prevent theme styles from stretching letters *\/\n    font-weight:600;\n    background:#f8fafc;\n  }\n\n  \/* Small screen optimization *\/\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\u003csection\u003e\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eWater Pump Impeller Kit – Fits Yamaha 20\/25\/30 HP Outboards \u0026amp; Mariner 20\/25\/30 HP (Replaces 689-W0078-A6\/689-W0078-A4)\u003c\/strong\u003e is designed to restore cooling system performance on a range of two-stroke outboards. It is engineered for Yamaha 25 HP and 30 HP models from 1984 through 1997 (including C25, CV25, C30, and CV30) and specific Mariner 20 HP, 25 HP, and 30 HP models including the 20C, 25C, and 30A which require serial number verification.\u003c\/p\u003e\n\u003cp\u003eThis comprehensive kit serves as a direct replacement for Yamaha part numbers 689-W0078-A6-00, 689-W0078-A4-00, and 689-W0078-04-00. It also cross-references with Sierra Marine 18-3426\/18-3427, GLM Marine 12059\/12058, and Mariner 42431M\/84829M\/97793M\/97793T.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eIncludes all necessary gaskets, seals, and hardware for a complete overhaul.\u003c\/li\u003e\n\u003cli\u003eEngineered for direct OEM-level fit and easy installation.\u003c\/li\u003e\n\u003cli\u003eDesigned for improved durability and higher flow rates for optimal engine cooling.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket brands.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\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\u003e689-W0078-A6-00\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A4-00\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-04-00\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra Marine\u003c\/td\u003e\n        \u003ctd\u003e18-3426\u003c\/td\u003e\n      \u003c\/tr\u003e\n       \u003ctr\u003e\n        \u003ctd\u003eSierra Marine\u003c\/td\u003e\n        \u003ctd\u003e18-3427\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM Marine\u003c\/td\u003e\n        \u003ctd\u003e12059\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM Marine\u003c\/td\u003e\n        \u003ctd\u003e12058\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e42431M\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e84829M\u003c\/td\u003e\n      \u003c\/tr\u003e\n       \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e97793M\u003c\/td\u003e\n      \u003c\/tr\u003e\n       \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e97793T\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model and year in the table below.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eFor Yamaha Owners:\u003c\/b\u003e This kit fits select 2-stroke 25 HP and 30 HP models manufactured between 1984 and 1997. Please verify your specific model (e.g., C25, CV30) and year carefully.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eFor Mariner Owners:\u003c\/b\u003e Fitment for models 20C, 25C, and 30A is dependent on the serial number prefix. Please verify your engine's serial number starts with 6A9 or 684 as indicated in the notes column.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine \u0026amp; Model Compatibility\"\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        \u003cth\u003eOEM Part No.\u003c\/th\u003e\n        \u003cth\u003eNotes\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\u003e25 HP\u003c\/td\u003e\n        \u003ctd\u003e25\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1984–1985\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e25 HP\u003c\/td\u003e\n        \u003ctd\u003e25\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1986–1987\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eC25\u003c\/td\u003e\n        \u003ctd\u003e25\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1991–1997\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eCV25\u003c\/td\u003e\n        \u003ctd\u003e25\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1990\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e30 HP\u003c\/td\u003e\n        \u003ctd\u003e30\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1986\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eC30\u003c\/td\u003e\n        \u003ctd\u003e30\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1991–1992\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eCV30\u003c\/td\u003e\n        \u003ctd\u003e30\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1989–1990\u003c\/td\u003e\n        \u003ctd\u003e689-W0078-A6-00\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e20C\u003c\/td\u003e\n        \u003ctd\u003e20\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eAll Years\u003c\/td\u003e\n        \u003ctd\u003e42431M\u003c\/td\u003e\n        \u003ctd\u003eS\/N prefix number 6A9\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e25C\u003c\/td\u003e\n        \u003ctd\u003e25\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eAll Years\u003c\/td\u003e\n        \u003ctd\u003e42431M\u003c\/td\u003e\n        \u003ctd\u003eS\/N prefix number 6A9\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e30A\u003c\/td\u003e\n        \u003ctd\u003e30\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eAll Years\u003c\/td\u003e\n        \u003ctd\u003e42431M\u003c\/td\u003e\n        \u003ctd\u003eS\/N prefix number 684\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n\u003cdd\u003eWater Pump Impeller Repair Kit\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect OEM Replacement\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eDesigned for durability with higher flow rates for optimal engine cooling\u003c\/dd\u003e\n\u003c\/dl\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1 x Water Pump Impeller (689-44352-02-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Woodruff Key (664-44338-00-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Pump Housing (689-44311-03-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Insert Cartridge (689-W4432-01-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Wear Plate (689-44323-02-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Gasket (689-44324-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Gasket (689-44315-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Water Seal (626-44365-01-00)\u003c\/li\u003e\n  \u003cli\u003e\u003cspan style=\"color:#d0021b;\"\u003e3 x Bolt with washer (97080-06030-00)\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the battery and shift the outboard into neutral.\u003c\/li\u003e\n  \u003cli\u003eUnbolt and remove the lower unit (gearcase) from the outboard's driveshaft housing. You may need to disconnect the shift linkage.\u003c\/li\u003e\n  \u003cli\u003eLocate and unbolt the water pump housing, typically found on top of the gearcase.\u003c\/li\u003e\n  \u003cli\u003eCarefully remove the old impeller, housing, wear plate, gaskets, and seals. Note the orientation of the impeller vanes.\u003c\/li\u003e\n  \u003cli\u003eClean all mating surfaces thoroughly, removing any old gasket material or corrosion.\u003c\/li\u003e\n  \u003cli\u003eInstall the new components from the kit in the reverse order of removal. Lightly grease the new impeller and insert it while turning the driveshaft clockwise to seat the vanes correctly.\u003c\/li\u003e\n  \u003cli\u003eEnsure all gaskets are properly aligned and torque the housing bolts to the manufacturer's specification.\u003c\/li\u003e\n  \u003cli\u003eReinstall the lower unit, connect the shift linkage, and test the engine in the water, confirming a steady stream from the tell-tale outlet.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I confirm this kit fits my engine?\u003c\/summary\u003e\u003cp\u003eCheck your engine's model, horsepower, and year against the compatibility table. For Mariner models, you must also verify your engine's serial number prefix matches the one listed in the notes.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat are the signs of a failing water pump impeller?\u003c\/summary\u003e\u003cp\u003eCommon symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the \"tell-tale\" outlet, and in some cases, a faint burning rubber smell from the exhaust.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow often should I replace my outboard's impeller?\u003c\/summary\u003e\u003cp\u003eAs a best practice for preventative maintenance, it is recommended to replace the impeller every 1-2 years or every 100-200 hours of use, whichever comes first, even if no issues are apparent. Refer to your engine's service manual for specific intervals.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat's the difference between the Yamaha -A6, -A4, and -04 kits?\u003c\/summary\u003e\u003cp\u003eThese are superseded part numbers from Yamaha. The -A6 part is the most recent OEM version, but this aftermarket kit is designed to replace all of them, providing the same fit and function.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eMy Mariner model is listed as \"All Years\". How do I confirm fitment?\u003c\/summary\u003e\u003cp\u003eFor the Mariner 20C, 25C, and 30A models, compatibility depends on the manufacturing run, which is identified by the serial number (S\/N) prefix. You must ensure your engine's S\/N prefix is either '6A9' or '684' as specified in our compatibility table.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this an OEM part or an aftermarket equivalent?\u003c\/summary\u003e\u003cp\u003eThis listing is for a high-quality aftermarket replacement part, not an OEM component. It has been manufactured in an ISO 9002 certified facility to meet or exceed OEM specifications for material and performance, and is batch-inspected for consistency.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow fast will my order ship?\u003c\/summary\u003e\u003cp\u003eWe ship worldwide, with most orders arriving within 5–15 business days. We offer free standard shipping, and expedited options are available at checkout for most destinations.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat is the warranty and return policy?\u003c\/summary\u003e\u003cp\u003eThis Water Pump Kit is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter a problem, please contact our support team with your order number. Unused parts in their original condition can be returned within our standard return window; check our policy page or contact us for details.\u003c\/p\u003e\u003c\/details\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVerify images and specifications against your original part before purchase. If anything differs—even if your model appears compatible—do not purchase.\u003c\/li\u003e\n\u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n\u003cli\u003eProfessional installation is recommended for safety and performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003ePro-Grade Standards\u003c\/b\u003e — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eFast Global Fulfillment\u003c\/b\u003e — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eManufacturer-Direct Value\u003c\/b\u003e — Fair pricing without compromising on materials or quality control.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723798057275,"sku":"20KY006","price":58.2,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_Kit_for_Yamaha_20_25_30_HP_689-W0078-A6_-_JLM_MARINE-8288778.jpg?v=1763032046","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-kit-fits-yamaha-mariner-20-30-hp-replaces-689-w0078-a6-a4-18-3426-3427","provider":"SeaSierra","version":"1.0","type":"link"}