{"product_id":"water-pump-impeller-fits-mercury-mariner-4-9-8-hp-outboards-replaces-47-89981","title":"Water Pump Impeller – Fits Mercury\/Mariner 4–9.8 HP Outboards (Replaces 47-89981)","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 4–9.8 HP Outboards (Replaces 47-89981)\u003c\/strong\u003e is designed for Mercury and Mariner 2-stroke outboard models from 3.9 HP to 10 HP (1965–1986) with an 11.60 mm shaft diameter. It ensures reliable engine cooling and performance.\u003c\/p\u003e\n\u003cp\u003eIt serves as a direct interchange for Mercury 47-89981, Sierra 18-3039, GLM 12270, CEF 500314, and Mallory 9-45305.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEngineered as a direct-fit replacement for specified models.\u003c\/li\u003e\n\u003cli\u003eConstructed with a durable brass hub and neoprene blades.\u003c\/li\u003e\n\u003cli\u003eNote: This part is not compatible with 5 HP Mercury Mariner engines.\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\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3039\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM\u003c\/td\u003e\n        \u003ctd\u003e12270\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      \u003ctr\u003e\n        \u003ctd\u003eMallory\u003c\/td\u003e\n        \u003ctd\u003e9-45305\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\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\u003e39 1-Cylinder\u003c\/td\u003e\n        \u003ctd\u003e3.9\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eSerial number 2278851 and up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e40 (4 HP) 1-Cylinder\u003c\/td\u003e\n        \u003ctd\u003e4\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eSerial number 2278851 and up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e4 HP 1-Cylinder USA\u003c\/td\u003e\n        \u003ctd\u003e4\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eInside diameter 0.456 inch\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e45, 4.5 1-Cylinder\u003c\/td\u003e\n        \u003ctd\u003e4.5\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eInside diameter 0.456 inch\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e60 (6HP)\u003c\/td\u003e\n        \u003ctd\u003e6\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eSerial number 1916139 thru 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\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eInside diameter 0.456 inch\u003c\/td\u003e\n      \u003c\/tr\u003e\n       \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e75 (7.5HP)\u003c\/td\u003e\n        \u003ctd\u003e7.5\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eInside diameter 0.456 inch\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\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\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eInside diameter 0.456 inch\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e110 (10hp)\u003c\/td\u003e\n        \u003ctd\u003e10\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1965–1986\u003c\/td\u003e\n        \u003ctd\u003e47-89981\u003c\/td\u003e\n        \u003ctd\u003eSerial number 1865779 and up\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-fit replacement\u003c\/dd\u003e\n \u003cdt\u003eFuel Type\u003c\/dt\u003e\n\u003cdd\u003eGasoline\u003c\/dd\u003e\n \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eBrass Hub with Neoprene Blades\u003c\/dd\u003e\n \u003cdt\u003eHousing Color\u003c\/dt\u003e\n\u003cdd\u003eBlack\u003c\/dd\u003e\n \u003cdt\u003eDimensions\u003c\/dt\u003e\n\u003cdd\u003eHeight: 14.40 mm (0.57\"), External Diameter: 32.00 mm (1.26\"), Internal Shaft Diameter: 11.60 mm (0.456\")\u003c\/dd\u003e\n \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003e11 g (0.39 oz)\u003c\/dd\u003e\n \u003cdt\u003eNumber of Blades\u003c\/dt\u003e\n\u003cdd\u003e6\u003c\/dd\u003e\n \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003eManufacturer warranty may apply\u003c\/dd\u003e\n \u003cdt\u003eOther Attributes\u003c\/dt\u003e\n\u003cdd\u003eNot compatible with 5 HP Mercury Mariner engines\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 remove the engine cover.\u003c\/li\u003e\n\u003cli\u003eDrain the lower unit gear lube.\u003c\/li\u003e\n\u003cli\u003eRemove the bolts securing the lower unit (gearcase) to the upper driveshaft housing.\u003c\/li\u003e\n\u003cli\u003eGently separate the lower unit from the upper housing. Be mindful of the shift shaft.\u003c\/li\u003e\n\u003cli\u003eLocate and unbolt the water pump housing.\u003c\/li\u003e\n\u003cli\u003eSlide the old impeller off the driveshaft, noting the keyway alignment.\u003c\/li\u003e\n\u003cli\u003eClean the housing and inspect for wear or damage. Lightly grease the new impeller and interior of the housing.\u003c\/li\u003e\n\u003cli\u003eInstall the new impeller onto the driveshaft, ensuring the key is in place and the blades are oriented correctly (typically bent in the direction of shaft rotation).\u003c\/li\u003e\n\u003cli\u003eReassemble the water pump housing, reattach the lower unit, and refill the gear lube with the correct type and amount.\u003c\/li\u003e\n\u003cli\u003eTest the engine in water, confirming a steady stream from the tell-tale port.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I know if this impeller fits my specific engine?\u003c\/summary\u003e\u003cp\u003eThis impeller fits a wide range of Mercury\/Mariner 2-stroke outboards from 3.9 to 9.8 HP made between 1965 and 1986. Please check the \"Engine \u0026amp; Model Compatibility\" table and verify your engine's model, horsepower, and serial number range. Crucially, this part is NOT for 5 HP models.\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 signs include a weak or non-existent water stream from the \"tell-tale\" outlet, engine overheating alerts or steam, and reduced engine performance. An impeller should be inspected regularly and replaced as part of routine maintenance.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow often should I replace my impeller?\u003c\/summary\u003e\u003cp\u003eFor preventative maintenance, it's recommended to replace the impeller every 1-2 years or every 100-200 hours of use, whichever comes first. Frequency should increase if operating in saltwater or sandy\/silty conditions.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes this include the housing or gaskets?\u003c\/summary\u003e\u003cp\u003eNo, this listing is for the impeller only, as shown in the \"What's in the Box\" section. It does not include the full water pump kit with housing, wear plate, or gaskets.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this an OEM or aftermarket part?\u003c\/summary\u003e\u003cp\u003eThis listing is for an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It is engineered to meet or exceed OEM specifications using comparable materials and is manufactured in an ISO 9001 certified facility, with batch inspections for quality control.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow much is shipping and how fast is it?\u003c\/summary\u003e\u003cp\u003eWe ship worldwide quickly, with a typical transit time of 5–15 days for most regions. Standard shipping is free. If available for your location, expedited shipping options and costs will be presented at checkout.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat is the warranty and return policy?\u003c\/summary\u003e\u003cp\u003eThis product is covered by a 1-year warranty against manufacturing defects under normal use conditions. Should you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard return window for items that are unused and in their original condition. See our full policy page or reach out for instructions.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVerify images and specifications against 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\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":50717909254459,"sku":"17IM003KOC","price":6.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/17IM003KOC.png?v=1762938183","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-fits-mercury-mariner-4-9-8-hp-outboards-replaces-47-89981","provider":"SeaSierra","version":"1.0","type":"link"}