{"product_id":"water-pump-impeller-repair-kit-fits-mercury-marine-15-20-efi-replaces-8m0135821-46-8m0135821","title":"Water Pump Impeller Repair Kit – Fits Mercury Marine 15-20 EFI (Replaces 8M0135821, 46-8M0135821)","description":"\u003csection\u003e\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eWater Pump Impeller Repair Kit\u003c\/strong\u003e is designed for Mercury Marine 15–20 HP EFI 4-Stroke outboard motors (2006–Present) with serial numbers 0R833820 and above, including ProKicker and SeaPro models. It provides all necessary components for routine cooling system maintenance and restoration.\u003c\/p\u003e\n\u003cp\u003eIt serves as a direct aftermarket replacement for Mercury part numbers 8M0135821 and 46-8M0135821, and provides an interchange for Sierra 18-7913 and QuickMarine 8M0135821.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEngineered as a direct OEM-spec replacement for a precise fit.\u003c\/li\u003e\n\u003cli\u003eAddresses common cooling system issues by replacing all wear items.\u003c\/li\u003e\n\u003cli\u003eKit includes the impeller, housing, wear plate, seals, and gaskets.\u003c\/li\u003e\n\u003c\/ul\u003e\n\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\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\u003e8M0135821\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e46-8M0135821\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-7913\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eQuickMarine\u003c\/td\u003e\n        \u003ctd\u003e8M0135821\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 is designed for specific Mercury Marine EFI 4-Stroke models from 2006 to the present with serial numbers 0R833820 and higher. Verify your model and serial number before ordering.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine 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\u003eEFI\u003c\/td\u003e\n        \u003ctd\u003e15\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2006–Present\u003c\/td\u003e\n        \u003ctd\u003e8M0135821\u003c\/td\u003e\n        \u003ctd\u003eSerial # 0R833820 \u0026amp; above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eEFI SeaPro\u003c\/td\u003e\n        \u003ctd\u003e15\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2006–Present\u003c\/td\u003e\n        \u003ctd\u003e8M0135821\u003c\/td\u003e\n        \u003ctd\u003eSerial # 0R833820 \u0026amp; above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eEFI ProKicker\u003c\/td\u003e\n        \u003ctd\u003e15\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2006–Present\u003c\/td\u003e\n        \u003ctd\u003e8M0135821\u003c\/td\u003e\n        \u003ctd\u003eSerial # 0R833820 \u0026amp; above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eEFI\u003c\/td\u003e\n        \u003ctd\u003e20\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2006–Present\u003c\/td\u003e\n        \u003ctd\u003e8M0135821\u003c\/td\u003e\n        \u003ctd\u003eSerial # 0R833820 \u0026amp; above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eEFI\u003c\/td\u003e\n        \u003ctd\u003e10\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2006–Present\u003c\/td\u003e\n        \u003ctd\u003e8M0135821\u003c\/td\u003e\n        \u003ctd\u003ePer PartsVu \u0026amp; Soxa Marine\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 OEM 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\u003ePlastic, Metal, Rubber\u003c\/dd\u003e\n  \u003cdt\u003eHousing Color\u003c\/dt\u003e\n\u003cdd\u003eBlack\/Silver\u003c\/dd\u003e\n  \u003cdt\u003eFitting Type\u003c\/dt\u003e\n\u003cdd\u003eVehicle Specific Fit\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eFor cooling system maintenance\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 (8M0135803)\u003c\/li\u003e\n  \u003cli\u003e1 x Housing (8M0134492)\u003c\/li\u003e\n  \u003cli\u003e1 x Insert Cup (803751)\u003c\/li\u003e\n  \u003cli\u003e1 x Wear Plate (8M0135805)\u003c\/li\u003e\n  \u003cli\u003e1 x Key (8M0137347)\u003c\/li\u003e\n  \u003cli\u003e1 x Oil Seal (803752)\u003c\/li\u003e\n  \u003cli\u003e1 x Seal (8036674)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cspan style=\"color:#d0021b;\"\u003e2 x Gaskets\u003c\/span\u003e (8M0135804, 8M0135806)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the negative battery cable and remove the upper shift linkage cover.\u003c\/li\u003e\n  \u003cli\u003eRemove the bolts securing the lower unit (gearcase) to the engine.\u003c\/li\u003e\n  \u003cli\u003eCarefully lower the gearcase to access the water pump assembly.\u003c\/li\u003e\n  \u003cli\u003eUnbolt and remove the old water pump housing and all its components.\u003c\/li\u003e\n  \u003cli\u003eThoroughly clean the driveshaft and all mating surfaces of old gasket material or corrosion.\u003c\/li\u003e\n  \u003cli\u003eInstall the new wear plate and gasket onto the gearcase.\u003c\/li\u003e\n  \u003cli\u003eSlide the new impeller onto the driveshaft with the new key, ensuring the vanes are oriented correctly.\u003c\/li\u003e\n  \u003cli\u003eInstall the new seals into the new housing and slide the assembly down over the impeller.\u003c\/li\u003e\n  \u003cli\u003eSecure the new housing with the original bolts, torqued to manufacturer specifications.\u003c\/li\u003e\n  \u003cli\u003eCarefully reinstall the lower unit, ensuring the driveshaft, water tube, and shift shaft align properly.\u003c\/li\u003e\n  \u003cli\u003eReconnect the shift linkage and battery. Start the engine in water and verify a strong tell-tale stream.\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 fits my engine?\u003c\/summary\u003e\n  \u003cp\u003eCheck that your engine is a Mercury 15–20 HP EFI 4-Stroke (2006+) and that its serial number is 0R833820 or higher. The most reliable method is to cross-reference your existing part number with those listed in our 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 \"telltale\" outlet, frequent engine overheating alarms, and a noticeable reduction in engine performance, especially at higher RPMs.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should this kit be used for maintenance?\u003c\/summary\u003e\n  \u003cp\u003eFor optimal reliability and to prevent overheating damage, we recommend inspecting the impeller annually and replacing it every 1–2 years or every 100–200 hours of operation, whichever occurs first.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eMy engine is a 10 HP EFI model. Is this compatible?\u003c\/summary\u003e\n  \u003cp\u003eWhile some aftermarket sources suggest compatibility with 10 HP EFI models from the same generation, we advise visually comparing your existing pump components to our product images and part numbers to guarantee a match before purchasing.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM part or an aftermarket equivalent?\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, it is batch-inspected for consistency and quality.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are your shipping speed and costs?\u003c\/summary\u003e\n  \u003cp\u003eWe ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free to most regions; expedited options will appear at checkout where available for your location.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the warranty and return policy?\u003c\/summary\u003e\n  \u003cp\u003eThis part is covered by a 1-year warranty against manufacturing defects under normal use. If any issues arise, please contact our support team with your order details. Returns are accepted within our standard window if the item is unused and in its 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 component, not an OEM part.\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 rigorously tested for real-world reliability.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — Enjoy free standard delivery to most regions, with typical transit times of 5–15 days.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — We deliver fair pricing on high-quality components 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":50717908107579,"sku":"QM-23KM774","price":75.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/QM-23KM774.png?v=1762938146","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-repair-kit-fits-mercury-marine-15-20-efi-replaces-8m0135821-46-8m0135821","provider":"SeaSierra","version":"1.0","type":"link"}