{"product_id":"water-pump-impeller-fits-mercury-marine-20-hp-replaces-47-89982-47-56780-47-65958-47-89982b","title":"Water Pump Impeller – Fits Mercury Marine 20 HP (Replaces 47-89982, 47-56780, 47-65958, 47-89982B)","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 *\/\ntable.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\ntable.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 *\/\ntable.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 – Fits Mercury Marine 20 HP (Replaces 47-89982)\u003c\/strong\u003e is an essential component for maintaining engine cooling in Mercury Marine 20 HP 2-Stroke outboard engines from model years 1970–1985. It ensures reliable water circulation to prevent overheating and maintain optimal performance.\u003c\/p\u003e\n\u003cp\u003eThis part provides a direct interchange for Mercury OEM numbers 47-56780, 47-65958, 47-89982, and 47-89982B, and is also equivalent to aftermarket parts from GLM (89820), Mallory (9-45311), and Sierra (18-3052).\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eInstalls in the lower gearcase to drive the engine's cooling system.\u003c\/li\u003e\n\u003cli\u003eConstructed from durable neoprene with a brass hub for corrosion resistance.\u003c\/li\u003e\n\u003cli\u003eA drive key is included in most kits for a complete replacement.\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\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-56780\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-65958\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-89982\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-89982B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGLM\u003c\/td\u003e\n\u003ctd\u003e89820\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMallory\u003c\/td\u003e\n\u003ctd\u003e9-45311\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3052\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\/year in the table below.\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\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e200\u003c\/td\u003e\n\u003ctd\u003e20\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1970–1985\u003c\/td\u003e\n\u003ctd\u003e47-89982\u003c\/td\u003e\n\u003ctd\u003eAlso listed as 47-56780, 47-65958, 47-89982B\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\u003c\/dd\u003e\n\u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eLower Gearcase\u003c\/dd\u003e\n\u003cdt\u003eConnection\u003c\/dt\u003e\n\u003cdd\u003eDriveshaft\u003c\/dd\u003e\n\u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eNeoprene with Brass Hub\u003c\/dd\u003e\n\u003cdt\u003eHousing Color\u003c\/dt\u003e\n\u003cdd\u003eBlack\/Brass\u003c\/dd\u003e\n\u003cdt\u003eFitting Type\u003c\/dt\u003e\n\u003cdd\u003eDirect Fit\u003c\/dd\u003e\n\u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eKey included with most replacement kits\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\u003cp\u003ePackage contents vary by manufacturer but typically include:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e1 x \u003cspan style=\"color:#d0021b;\"\u003eWater Pump Impeller (47-89982)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x \u003cspan style=\"color:#d0021b;\"\u003eDrive Key\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSome kits may additionally include:\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003e1 x Face Plate\u003c\/li\u003e\n    \u003cli\u003e1 x Plate Gasket\u003c\/li\u003e\n    \u003cli\u003e1 x Slinger\u003c\/li\u003e\n    \u003cli\u003e1 x O-Ring\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\u003eDrain the gearcase oil from the lower unit.\u003c\/li\u003e\n\u003cli\u003eUnbolt and carefully lower the gearcase from the outboard's driveshaft housing.\u003c\/li\u003e\n\u003cli\u003eRemove the bolts securing the water pump housing to the gearcase.\u003c\/li\u003e\n\u003cli\u003eSlide the old pump housing and impeller off the driveshaft. Note the orientation of the old impeller vanes.\u003c\/li\u003e\n\u003cli\u003eClean the driveshaft and housing interior, removing any debris or gasket residue.\u003c\/li\u003e\n\u003cli\u003eInstall the new drive key and slide the new impeller onto the driveshaft. Rotate the driveshaft clockwise to bend the vanes correctly.\u003c\/li\u003e\n\u003cli\u003eApply a light coat of marine grease or soap to the inside of the new housing and install it over the impeller.\u003c\/li\u003e\n\u003cli\u003eReinstall the water pump bolts, lower unit, and refill the gearcase with fresh oil before starting the engine.\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\n\u003csummary\u003eHow do I know if my water pump impeller is failing?\u003c\/summary\u003e\n\u003cp\u003eCommon signs of a worn or damaged impeller include an engine overheating alarm, a weak or non-existent water stream from the \"tell-tale\" outlet, or an unusually high reading on your temperature gauge. Visual inspection during routine maintenance is the best way to catch wear before it causes a failure.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the recommended replacement interval for an impeller?\u003c\/summary\u003e\n\u003cp\u003eFor most outboard engines, it is recommended to replace the water pump impeller every 1 to 2 years or every 100-200 hours of operation, whichever comes first. This interval can be shorter if you frequently operate in sandy, silty, or saltwater conditions.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhy are the impeller vanes bent?\u003c\/summary\u003e\n\u003cp\u003eThe flexible neoprene vanes are designed to bend inside the offset water pump housing. As the driveshaft spins, the vanes flex and straighten, creating suction to draw water in and pressure to push it up into the engine's cooling passages.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs this a difficult part to install?\u003c\/summary\u003e\n\u003cp\u003eInstallation requires lowering the gearcase, which can be done by individuals with moderate mechanical skill and the correct tools. However, due to the importance of correct assembly for engine safety, professional installation is recommended to prevent cooling system failures.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eOEM vs. Aftermarket?\u003c\/summary\u003e\n\u003cp\u003eThis listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eShipping speed \u0026amp; cost\u003c\/summary\u003e\n\u003cp\u003eWe ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWarranty \u0026amp; returns\u003c\/summary\u003e\n\u003cp\u003eCovered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused \u0026amp; in original condition). See our policy page or reach out for instructions.\u003c\/p\u003e\n\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\/specifications vs your original part. 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\u003cstrong\u003ePro-Grade Standards\u003c\/strong\u003e — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — Fair pricing without compromising on materials or QC.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723792159035,"sku":"17IO002-K-QM","price":18.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/17IO002-K-QM.png?v=1763031907","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-fits-mercury-marine-20-hp-replaces-47-89982-47-56780-47-65958-47-89982b","provider":"SeaSierra","version":"1.0","type":"link"}