{"product_id":"water-pump-impeller-kit-fits-mercury-4-9-8-hp-replaces-46-70941a3","title":"Water Pump Impeller Kit – Fits Mercury 4–9.8 HP (Replaces 46-70941A3)","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 \u003cstrong\u003eWater Pump Impeller Kit – Fits Mercury 4–9.8 HP (Replaces 46-70941A3)\u003c\/strong\u003e is designed for Mercury Marine 2-stroke outboard motors, including 4 HP, 4.5 HP, 7.5 HP, and 9.8 HP models manufactured between 1975 and 1986. It restores cooling system performance to prevent overheating and ensure engine reliability.\u003c\/p\u003e\n\u003cp\u003eIt serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 46-70941A3, Sierra 18-3446, GLM 12122, and Sierra 18-3447, offering a versatile cross-reference solution.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEngineered for direct-fit installation.\u003c\/li\u003e\n\u003cli\u003eRestores cooling system integrity and water pressure.\u003c\/li\u003e\n\u003cli\u003eIncludes all essential components for a standard service.\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\u003e46-70941A3\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3446\u003c\/td\u003e\n      \u003c\/tr\u003e\n        \u003ctr\u003e\n        \u003ctd\u003eGLM\u003c\/td\u003e\n        \u003ctd\u003e12122\u003c\/td\u003e\n      \u003c\/tr\u003e\n        \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3447\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\u003eOutboard\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\u003e46-70941A3\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eOutboard\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\u003e46-70941A3\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eOutboard\u003c\/td\u003e\n        \u003ctd\u003e7.5\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1975–1986\u003c\/td\u003e\n        \u003ctd\u003e46-70941A3\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eOutboard\u003c\/td\u003e\n        \u003ctd\u003e9.8 (Model 110)\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1975–1986\u003c\/td\u003e\n        \u003ctd\u003e46-70941A3\u003c\/td\u003e\n        \u003ctd\u003e\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 Kit\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect replacement\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n    \u003cli\u003eImpeller\u003c\/li\u003e\n    \u003cli\u003eGaskets\/O-rings\u003c\/li\u003e\n    \u003cli\u003eAdditional components typically found in water pump service kits\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\u003ePlace a drain pan under the lower unit and remove the drain\/fill screws to empty the gear oil.\u003c\/li\u003e\n    \u003cli\u003eRemove the bolts securing the lower unit (gearcase) to the engine's midsection.\u003c\/li\u003e\n    \u003cli\u003eCarefully lower the gearcase to access the water pump housing.\u003c\/li\u003e\n    \u003cli\u003eUnbolt and remove the water pump housing to expose the old impeller.\u003c\/li\u003e\n    \u003cli\u003eNote the orientation of the old impeller vanes before removing it.\u003c\/li\u003e\n    \u003cli\u003eClean the housing interior and replace gaskets, seals, and the wear plate.\u003c\/li\u003e\n    \u003cli\u003eInstall the new impeller, turning the driveshaft clockwise to bend the vanes correctly.\u003c\/li\u003e\n    \u003cli\u003eReinstall the housing, ensuring a proper seal.\u003c\/li\u003e\n    \u003cli\u003eReattach the lower unit, refill with fresh gear oil, and reconnect the battery\/plugs.\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\n    \u003csummary\u003eHow do I confirm this kit fits my specific engine?\u003c\/summary\u003e\n    \u003cp\u003eCheck your engine's model, horsepower, and year. Compare it against the \"Engine \u0026amp; Model Compatibility\" table. You can also verify by cross-referencing your existing part number with those in the \"Part Number Matrix\".\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 symptoms include a weak or non-existent water stream from the \"tell-tale\" outlet, engine overheating alarms, and reduced engine performance. Visible damage to the old impeller, like cracked, brittle, or missing vanes, also indicates it needs replacement.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eHow often should I replace my impeller?\u003c\/summary\u003e\n    \u003cp\u003eAs a general maintenance rule, it is recommended to inspect and\/or replace the water pump impeller every 1–2 years or every 100–200 hours of operation, depending on usage conditions (e.g., more frequently in saltwater or sandy\/silty environments).\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eWhat is the difference between this kit and an OEM one?\u003c\/summary\u003e\n    \u003cp\u003eOur aftermarket kits are engineered to meet or exceed original equipment manufacturer (OEM) specifications for fit, form, and function. They are made with comparable materials in an ISO 9002-certified facility and offer a cost-effective alternative to genuine parts without sacrificing quality.\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\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\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723968876859,"sku":"18KM005","price":52.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_Kit_for_Mercury_4-98_HP__46-70941A3_-_JLM_MARINE-8286329.jpg?v=1763038735","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-kit-fits-mercury-4-9-8-hp-replaces-46-70941a3","provider":"SeaSierra","version":"1.0","type":"link"}