{"product_id":"water-pump-impeller-repair-kit-fits-mercury-marine-4-9-8-hp-replaces-46-70941a3","title":"Water Pump Impeller Repair Kit – Fits Mercury Marine 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 Repair Kit\u003c\/strong\u003e is designed for Mercury Marine 4 HP, 4.5 HP, 7.5 HP, and 9.8 HP 2-Stroke outboard motors manufactured between 1975 and 1986. It provides all the necessary components to restore your engine's cooling system to factory specifications, preventing overheating and ensuring reliable performance.\u003c\/p\u003e\n  \u003cp\u003eIt serves as a direct interchange for Mercury 46-70941A3, Sierra 18-3446, GLM 12122, and QuickMarine 70941A3, ensuring a precise fit and function.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eEngineered for direct replacement, simplifying installation.\u003c\/li\u003e\n    \u003cli\u003eConstructed with durable materials: a CR-Neoprene impeller, nylon housing, and a stainless steel (SS316) face plate for longevity.\u003c\/li\u003e\n    \u003cli\u003eKit includes a comprehensive set of seals, O-rings, and hardware for a complete 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\u003eQuickMarine\u003c\/td\u003e\n\u003ctd\u003e70941A3\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\u003eThis kit fits specific serial number ranges for Mercury outboards. Please verify your engine's serial number falls within the specified ranges to ensure correct fitment.\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\u003eSerial 5595532 \u0026amp; UP (Made in USA)\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\u003eSerial 4107220-5595531 and 5595532 \u0026amp; UP\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003eOutboard\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1975–1982\u003c\/td\u003e\n\u003ctd\u003e46-70941A3\u003c\/td\u003e\n\u003ctd\u003eSerial 1582403-1916138, 1916139-2193817, 2193818-2529894, 2385673-2387383\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\u003eSerial 2529895-4131609, 4131610-5226934, 5206550 \u0026amp; UP\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\u003eSerial 1865779-2196388, 2196389-3795657, 3795658-4126459, 4126460-5206549, 5206550 \u0026amp; 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 Repair Kit\u003c\/dd\u003e\n    \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect replacement\u003c\/dd\u003e\n    \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eNylon\u003c\/dd\u003e\n    \u003cdt\u003eImpeller Material\u003c\/dt\u003e\n\u003cdd\u003eCR-Neoprene\u003c\/dd\u003e\n    \u003cdt\u003eFace Plate Material\u003c\/dt\u003e\n\u003cdd\u003eStainless Steel (SS316)\u003c\/dd\u003e\n    \u003cdt\u003eImpeller Insert Size\u003c\/dt\u003e\n\u003cdd\u003e0.456 inches (11.6 mm) diameter\u003c\/dd\u003e\n    \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003e30-day returns (Amazon); 1-year (JLM Marine)\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\u003c\/li\u003e\n    \u003cli\u003e1 x Impeller Plate (Face Plate)\u003c\/li\u003e\n    \u003cli\u003e1 x Water Pump Cover Seal\u003c\/li\u003e\n    \u003cli\u003e1 x Cover Assembly\u003c\/li\u003e\n    \u003cli\u003e1 x Housing Assembly\u003c\/li\u003e\n    \u003cli\u003e1 x Key\u003c\/li\u003e\n    \u003cli\u003e1 x Seal\u003c\/li\u003e\n    \u003cli\u003e1 x Washer\u003c\/li\u003e\n    \u003cli\u003e\u003cspan style=\"color:#d0021b;\"\u003e1 x O-ring (25-62704, 29439)\u003c\/span\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003cspan style=\"color:#d0021b;\"\u003e1 x Rubber Ring (26-30526)\u003c\/span\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003cspan style=\"color:#d0021b;\"\u003e1 x Oil Seal O-ring (26-30913)\u003c\/span\u003e\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 spark plug wires for safety.\u003c\/li\u003e\n    \u003cli\u003eDrain the lower unit gear lube.\u003c\/li\u003e\n    \u003cli\u003eRemove the lower unit (gearcase) from the outboard motor.\u003c\/li\u003e\n    \u003cli\u003eUnbolt and remove the old water pump housing assembly.\u003c\/li\u003e\n    \u003cli\u003eClean the mounting surfaces and inspect the driveshaft for wear or damage.\u003c\/li\u003e\n    \u003cli\u003eInstall the new key, impeller, face plate, and gaskets from the kit.\u003c\/li\u003e\n    \u003cli\u003eLightly grease the interior of the new housing and install it over the impeller, ensuring the impeller vanes are correctly oriented.\u003c\/li\u003e\n    \u003cli\u003eSecure the new housing with the provided hardware and torque to manufacturer specifications.\u003c\/li\u003e\n    \u003cli\u003eRe-install the lower unit, refill with fresh gear lube, and reconnect the battery and spark plugs.\u003c\/li\u003e\n    \u003cli\u003eStart the engine in water and verify a steady stream from the cooling system's tell-tale outlet.\u003c\/li\u003e\n  \u003c\/ol\u003e\n\n  \u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n  \u003cdetails\u003e\u003csummary\u003eHow do I confirm this kit fits my motor?\u003c\/summary\u003e\u003cp\u003eVerify your outboard's model, year, and especially its serial number against the ranges listed in the Engine \u0026amp; Model Compatibility table. Fitment is specific to these serial number breaks.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhat are common signs of a failing water pump impeller?\u003c\/summary\u003e\u003cp\u003eThe most common symptoms are a weak or non-existent water stream from the tell-tale outlet, an engine overheating alarm, or a noticeable decrease in engine performance as the ECU reduces power to prevent damage.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eHow often should I replace the impeller?\u003c\/summary\u003e\u003cp\u003eFor preventative maintenance, it is recommended to replace the impeller every 1 to 2 years, or every 100-200 hours of operation. Replacement frequency should increase if you operate in saltwater or water with high sediment content.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhat is the benefit of a CR-Neoprene impeller?\u003c\/summary\u003e\u003cp\u003eCR-Neoprene is a robust, flexible synthetic rubber that offers excellent resistance to heat, saltwater, oil, and abrasion, providing greater durability and a longer service life compared to standard rubber compounds.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhy does this kit include so many O-rings and seals?\u003c\/summary\u003e\u003cp\u003eThis kit is designed to be comprehensive, providing all necessary seals for various serial number ranges covered by the part number. This ensures you have the correct components on hand for a complete and reliable repair without needing to source extra parts.\u003c\/p\u003e\u003c\/details\u003e\n   \u003cdetails\u003e\u003csummary\u003eIs the water pump housing included?\u003c\/summary\u003e\u003cp\u003eYes, this is a complete repair kit that includes the nylon housing assembly, impeller, face plate, and all required gaskets, seals, and hardware for a full replacement.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eOEM vs. Aftermarket?\u003c\/summary\u003e\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\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eShipping speed \u0026amp; cost?\u003c\/summary\u003e\u003cp\u003eWe ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWarranty \u0026amp; returns?\u003c\/summary\u003e\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\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\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723968844091,"sku":"18KM005-QM","price":23.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/18KM005-QM.png?v=1763038733","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-repair-kit-fits-mercury-marine-4-9-8-hp-replaces-46-70941a3","provider":"SeaSierra","version":"1.0","type":"link"}