{"product_id":"water-pump-impeller-fits-mercury-3-9-9-8-hp-outboards-replaces-mercury-47-89981","title":"Water Pump Impeller – Fits Mercury 3.9-9.8 HP Outboards (Replaces Mercury 47-89981)","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 aftermarket \u003cstrong\u003eWater Pump Impeller – Fits Mercury 3.9-9.8 HP Outboards (Replaces 47-89981)\u003c\/strong\u003e is designed for specific Mercury 1-cylinder 4 HP (1982–1985), 4.5 HP (1980–1985), 7.5 HP (1979–1986), and 9.8 HP (1979–1985) 2-Stroke outboards that use a 0.456\" diameter driveshaft. It is crucial to verify your driveshaft size, as this part will not fit models with smaller shafts or any 5 HP Mercury\/Mariner engines.\u003c\/p\u003e\n  \u003cp\u003eIt serves as a direct replacement for Mercury part numbers 47-89981, 47-89981Q1, 47-89981T1, and 47-89981T2, and interchanges with equivalents from Sierra, GLM, Mallory, and SEI Marine.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eMade from durable neoprene rubber with a brass hub for corrosion resistance.\u003c\/li\u003e\n    \u003cli\u003eEngineered for the larger 0.456\" outer diameter driveshaft version.\u003c\/li\u003e\n    \u003cli\u003eIncludes one water pump impeller as pictured.\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 Cross-Reference\"\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, 47-89981Q1, 47-89981T1, 47-89981T2\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, 89810\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        \u003ctr\u003e\n          \u003ctd\u003eSEI Marine\u003c\/td\u003e\n          \u003ctd\u003e96-260-03B\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\u003eFitment for these Mercury models is highly dependent on the serial number and driveshaft diameter. This impeller is for models with a 0.456\" driveshaft. Please verify your specific application before ordering.\u003c\/p\u003e\n  \u003cdiv class=\"ss-table-wrap\"\u003e\n    \u003ctable class=\"ss-table\" aria-label=\"Engine Compatibility List\"\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\u003e1-cylinder\u003c\/td\u003e\n          \u003ctd\u003e4\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1982–1985\u003c\/td\u003e\n          \u003ctd\u003e47-89981\u003c\/td\u003e\n          \u003ctd\u003eS\/N 2498136-4107219\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eMercury\u003c\/td\u003e\n          \u003ctd\u003e-\u003c\/td\u003e\n          \u003ctd\u003e4.5\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1980–1985\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\u003e-\u003c\/td\u003e\n          \u003ctd\u003e7.5\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 4131610 and up\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eMercury\u003c\/td\u003e\n          \u003ctd\u003e(Model 110)\u003c\/td\u003e\n          \u003ctd\u003e9.8\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1979–1985\u003c\/td\u003e\n          \u003ctd\u003e47-89981\u003c\/td\u003e\n          \u003ctd\u003eS\/N 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\u003eMaterial\u003c\/dt\u003e\n\u003cdd\u003eNeoprene rubber with brass hub\u003c\/dd\u003e\n    \u003cdt\u003eNumber of Blades\u003c\/dt\u003e\n\u003cdd\u003e6\u003c\/dd\u003e\n    \u003cdt\u003eImpeller Height\u003c\/dt\u003e\n\u003cdd\u003e11.6 mm (0.456 inch)\u003c\/dd\u003e\n    \u003cdt\u003eOverall Diameter\u003c\/dt\u003e\n\u003cdd\u003e32 mm (1.260 inch)\u003c\/dd\u003e\n    \u003cdt\u003eShaft Diameter\u003c\/dt\u003e\n\u003cdd\u003e14.4 mm (0.567 inch)\u003c\/dd\u003e\n    \u003cdt\u003eDriveshaft Size\u003c\/dt\u003e\n\u003cdd\u003e0.456 inch outer diameter\u003c\/dd\u003e\n    \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003e10 g (0.022 lb)\u003c\/dd\u003e\n    \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003e1 Year (aftermarket)\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 completely.\u003c\/li\u003e\n    \u003cli\u003eRemove the bolts securing the lower unit (gearcase) to the engine's midsection.\u003c\/li\u003e\n    \u003cli\u003eCarefully separate and lower the gearcase from the driveshaft housing.\u003c\/li\u003e\n    \u003cli\u003eLocate and unbolt the water pump housing on top of the gearcase to expose the old impeller.\u003c\/li\u003e\n    \u003cli\u003eRemove the old impeller, noting the original orientation of the blades.\u003c\/li\u003e\n    \u003cli\u003eClean the housing interior and inspect it for wear or damage.\u003c\/li\u003e\n    \u003cli\u003eInstall the new impeller, using a twisting motion in the direction of engine rotation to bend the blades correctly.\u003c\/li\u003e\n    \u003cli\u003eApply a light coat of marine grease or soapy water to the new impeller and housing.\u003c\/li\u003e\n    \u003cli\u003eReassemble the water pump, gearcase, and all components in reverse order, ensuring proper alignment and torque on all bolts.\u003c\/li\u003e\n    \u003cli\u003eRefill the gearcase with the correct type and amount of lube.\u003c\/li\u003e\n    \u003cli\u003eTest the engine in water to confirm a strong, steady stream from the telltale 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 fits my Mercury outboard?\u003c\/summary\u003e\n    \u003cp\u003eThis impeller is specifically for older Mercury 3.9 HP to 9.8 HP models that use a \u003cstrong\u003e0.456-inch diameter driveshaft\u003c\/strong\u003e. You must verify this dimension. It will not fit models with a smaller driveshaft or any 5 HP engines. Check the compatibility table and your engine's serial number range for a precise match.\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 overheating at idle or low speeds, a weak or non-existent stream of water from the \"telltale\" outlet, and a dry, cracked, or brittle appearance of the old impeller upon inspection.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should the water pump impeller be replaced?\u003c\/summary\u003e\n    \u003cp\u003eAs a general maintenance guideline, it is recommended to inspect the impeller annually and replace it every 1–2 years or every 100–200 hours of use, whichever comes first. This interval can be shorter if you frequently operate in sandy or silty water.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eThe new impeller looks slightly different from my original. Can I still use it?\u003c\/summary\u003e\n    \u003cp\u003eNo. While aftermarket parts may have minor cosmetic differences, the critical dimensions (height, diameter, shaft size, number of blades) must match exactly. If there are any discrepancies, do not install the part. This impeller has 6 blades and is 11.6 mm tall.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs a gasket included with this part?\u003c\/summary\u003e\n    \u003cp\u003eThis listing is for the impeller only, as shown in the \"What’s in the Box\" section. Gaskets, housing, and other components of a full water pump repair kit are sold separately.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat is the main cause of premature impeller failure?\u003c\/summary\u003e\n    \u003cp\u003eThe most common cause is running the outboard \"dry\" (out of the water) for even a few seconds. Water acts as both a coolant and lubricant for the impeller. Without it, the rubber quickly overheats and can be permanently damaged.\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). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility and 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 is 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 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 quality control.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723964092731,"sku":"17IM003","price":20.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_for_Mercury_39-98_HP_47-89981_-_JLM_MARINE-8289780.jpg?v=1763038532","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-fits-mercury-3-9-9-8-hp-outboards-replaces-mercury-47-89981","provider":"SeaSierra","version":"1.0","type":"link"}