{"product_id":"water-pump-impeller-fits-mercury-mariner-4-9-8hp-outboards-replaces-47-89981-47-65957-47-39074","title":"Water Pump Impeller – Fits Mercury\/Mariner 4–9.8HP Outboards (Replaces 47-89981, 47-65957, 47-39074)","description":"\u003csection\u003e\n\u003c!-- 🔧 Table Styles (include only once per page) --\u003e\n\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\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis replacement \u003cstrong\u003eWater Pump Impeller – Fits Mercury\/Mariner 4–9.8HP Outboards\u003c\/strong\u003e is engineered for a precise fit on select 2-stroke engines from 1975–1986, specifically models with a 0.456\" (11.6mm) drive shaft diameter. It is a crucial component for maintaining proper engine cooling performance by circulating water through the outboard's cooling system.\u003c\/p\u003e\n\u003cp\u003eThis part serves as a direct interchange for OEM numbers Mercury 47-89981, 47-65957, and 47-39074, and aftermarket equivalents including Sierra 18-3039, GLM 89810, and Mallory 9-45305.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eInstalls via a direct press-fit on the drive shaft.\u003c\/li\u003e\n  \u003cli\u003eConstructed from durable neoprene with a brass hub for corrosion resistance.\u003c\/li\u003e\n  \u003cli\u003eCritically designed for models using the larger 0.456\" diameter drive shaft.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket.\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\u003e47-89981\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-89981B\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-65957\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-39074\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3039\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eGLM Marine\u003c\/td\u003e\n\u003ctd\u003e89810\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory Marine\u003c\/td\u003e\n\u003ctd\u003e9-45305\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory Marine\u003c\/td\u003e\n\u003ctd\u003e9-45305-10\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSEI Marine\u003c\/td\u003e\n\u003ctd\u003e96-260-03B\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eCEF\u003c\/td\u003e\n\u003ctd\u003e500310\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eCEF\u003c\/td\u003e\n\u003ctd\u003e500314\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\u003cp\u003eFor Mercury and Mariner owners: Please measure your drive shaft diameter. This impeller is only compatible with the 0.456-inch shaft. It will not fit models with the smaller shaft diameter, even if your model and year fall within the listed ranges.\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\u003e4 HP\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1975–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 2498136-4107219 (1 cylinder)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e4 HP\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1979–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 5595532-9075838 (USA model)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e4.5 HP\u003c\/td\u003e\n\u003ctd\u003e4.5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1975–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 4107220 and up\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e6 HP\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1976–1979\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 1916139-2193817\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e6 HP\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1979–1983\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 2193818-2529894\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e7.5 HP\u003c\/td\u003e\n\u003ctd\u003e7.5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1976–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 4131610-5226934\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e9.8 HP (110)\u003c\/td\u003e\n\u003ctd\u003e9.8\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1976–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eS\/N 2196389-5206549\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMariner\u003c\/td\u003e\n\u003ctd\u003e4 HP\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1977–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eWith 0.456\" drive shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMariner\u003c\/td\u003e\n\u003ctd\u003e4.5 HP\u003c\/td\u003e\n\u003ctd\u003e4.5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1977–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eWith 0.456\" drive shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMariner\u003c\/td\u003e\n\u003ctd\u003e6 HP\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1977–1983\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eWith 0.456\" drive shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMariner\u003c\/td\u003e\n\u003ctd\u003e7.5 HP\u003c\/td\u003e\n\u003ctd\u003e7.5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1977–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eWith 0.456\" drive shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMariner\u003c\/td\u003e\n\u003ctd\u003e9.8 HP\u003c\/td\u003e\n\u003ctd\u003e9.8\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1977–1986\u003c\/td\u003e\n\u003ctd\u003e47-89981\u003c\/td\u003e\n\u003ctd\u003eWith 0.456\" drive shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\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\u003eDirect Replacement\u003c\/dd\u003e\n  \u003cdt\u003eFuel Type\u003c\/dt\u003e\n\u003cdd\u003eGasoline\u003c\/dd\u003e\n  \u003cdt\u003eConnection\u003c\/dt\u003e\n\u003cdd\u003ePress-fit on Drive Shaft\u003c\/dd\u003e\n  \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eNeoprene with Metal (Brass) Hub\u003c\/dd\u003e\n  \u003cdt\u003eHousing Color\u003c\/dt\u003e\n\u003cdd\u003eBlack\u003c\/dd\u003e\n  \u003cdt\u003eDimensions\u003c\/dt\u003e\n\u003cdd\u003eOverall Diameter: 32.0mm (1.26\"), Height: 14.4mm (0.57\"), Hub Shaft Diameter: 11.6mm (0.456\")\u003c\/dd\u003e\n  \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003e~11g (0.4 oz)\u003c\/dd\u003e\n  \u003cdt\u003eNumber of Blades\u003c\/dt\u003e\n\u003cdd\u003e6\u003c\/dd\u003e\n  \u003cdt\u003eOperating Temperature\u003c\/dt\u003e\n\u003cdd\u003e-29°C to 82°C (-20°F to 180°F)\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1 x Water Pump Impeller (47-89981)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the battery and spark plug wires for safety.\u003c\/li\u003e\n  \u003cli\u003eDrain the lower unit gear lube.\u003c\/li\u003e\n  \u003cli\u003eRemove the bolts securing the lower unit (gearcase) and carefully separate it from the upper housing.\u003c\/li\u003e\n  \u003cli\u003eUnbolt and remove the water pump housing cover to access the old impeller. Note the orientation of the blades.\u003c\/li\u003e\n  \u003cli\u003eRemove the old impeller. Clean the housing interior and inspect it for wear or damage.\u003c\/li\u003e\n  \u003cli\u003eLubricate the new impeller and housing with a suitable marine grease or soapy water.\u003c\/li\u003e\n  \u003cli\u003eInstall the new impeller, ensuring the blades are oriented in the correct rotational direction (typically by turning the driveshaft clockwise while pushing down).\u003c\/li\u003e\n  \u003cli\u003eReinstall the water pump housing, using new gaskets where applicable, and tighten bolts to the manufacturer's specified torque.\u003c\/li\u003e\n  \u003cli\u003eReattach the lower unit, refill the gear lube, and reconnect the battery\/spark plugs.\u003c\/li\u003e\n  \u003cli\u003eStart the engine in water and verify a strong, steady stream from the \"tell-tale\" water outlet.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I know if this impeller will fit my Mercury or Mariner engine?\u003c\/summary\u003e\n  \u003cp\u003eFirst, confirm your model and year in the compatibility chart. Most importantly, you must verify your engine has the 0.456-inch (11.6mm) diameter drive shaft. Mercury used two different shaft sizes on these HP ranges, so physical measurement is the only way to be certain.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are the signs of a failing water pump impeller?\u003c\/summary\u003e\n  \u003cp\u003eCommon signs include the engine running hotter than normal, a weak or non-existent water stream from the \"tell-tale\" outlet, or a melted water pump housing. If you notice any of these symptoms, shut down the engine immediately to prevent overheating and severe damage.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should I replace my impeller?\u003c\/summary\u003e\n  \u003cp\u003eFor preventative maintenance, it is best practice to replace the impeller every year or every 100 hours of operation, whichever comes first. This is especially important if you operate in saltwater or sandy\/silty conditions.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this part compatible with Mercury 5HP engines?\u003c\/summary\u003e\n  \u003cp\u003eNo, it is not. Mercury\/Mariner 5HP outboards typically use a different impeller, part number 47-16154-3.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhy is verifying the shaft diameter so critical?\u003c\/summary\u003e\n  \u003cp\u003eDuring the same production years, Mercury produced 4, 4.5, and 7.5 HP motors with two different drive shaft diameters. An impeller designed for the wrong shaft size will not fit or function, leading to immediate engine overheating. Always measure before ordering.\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\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\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003ePro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n  \u003cli\u003eFast Global Fulfillment — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n  \u003cli\u003eManufacturer-Direct Value — 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":50723968811323,"sku":"fys12111236","price":11.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/fys12111236.png?v=1763038731","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-fits-mercury-mariner-4-9-8hp-outboards-replaces-47-89981-47-65957-47-39074","provider":"SeaSierra","version":"1.0","type":"link"}