{"product_id":"heavy-duty-sea-water-pump-impeller-kit-fits-mercury-mercruiser-4-5l-6-2l-mcm-mie-towsport-models-replaces-47-8m0137221","title":"Heavy Duty Sea Water Pump Impeller Kit – Fits Mercury MerCruiser 4.5L, 6.2L MCM, MIE \u0026 TowSport Models (Replaces 47-8M0137221)","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\u003eHeavy Duty Sea Water Pump Impeller Kit\u003c\/strong\u003e is designed as a direct-fit replacement for specific Mercury MerCruiser engines. It is engineered for late-model MerCruiser 4.5L engines (serial numbers 2A531163 and up) and 6.2L MCM (sterndrive), MIE (inboard), and TowSport models (serial numbers 2A531197+, 2A530774+, and 2A531348+ respectively).\u003c\/p\u003e\n\u003cp\u003eThis kit serves as a direct replacement for Mercury\/MerCruiser part numbers 47-8M0137221 and the superseded part 98-8M0121940.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eInstalls directly in the OEM sea water pump housing.\u003c\/li\u003e\n\u003cli\u003eFeatures a robust 8-blade design for efficient water flow.\u003c\/li\u003e\n\u003cli\u003eKit includes the impeller, wear plates, and seal 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        \u003cth\u003eSuperseded By\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\/MerCruiser\u003c\/td\u003e\n        \u003ctd\u003e98-8M0121940\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\/MerCruiser\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\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\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\u003cp\u003eFor Mercury models, it is critical to verify your engine's serial number against the requirements listed in the 'Notes' column 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\u003eMerCruiser 4.5L\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eRequires serial number 2A531163 and above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMerCruiser 6.2L MCM (sterndrive)\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eRequires serial number 2A531197 and above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMerCruiser 6.2L MIE (inboard)\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eRequires serial number 2A530774 and above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMerCruiser 6.2L TowSport\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eRequires serial number 2A531348 and above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMerCruiser 4.3L MPI\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eBased on MarineEngineParts listing\u003c\/td\u003e\n      \u003c\/tr\u003e\n       \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMerCruiser 5.0L MPI\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eBased on MarineEngineParts listing\u003c\/td\u003e\n      \u003c\/tr\u003e\n       \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMerCruiser 350 MAG MPI\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n        \u003ctd\u003e47-8M0137221\u003c\/td\u003e\n        \u003ctd\u003eBased on MarineEngineParts listing\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\u003eHeavy Duty Sea Water Pump Impeller Kit\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect replacement\u003c\/dd\u003e\n  \u003cdt\u003eDimensions\u003c\/dt\u003e\n\u003cdd\u003eImpeller Diameter: 2-5\/8\" (66.7 mm), Impeller Length: 2\" (50.8 mm)\u003c\/dd\u003e\n  \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003e1.00 lb (0.45 kg)\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003e8 blade impeller, 0.030\" shorter than standard\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 \u003cspan style=\"color:#d0021b;\"\u003eShorter Heavy Duty Impeller (8M0103389)\u003c\/span\u003e\n\u003c\/li\u003e\n  \u003cli\u003e1 x Rear Wear Plate\u003c\/li\u003e\n  \u003cli\u003e1 x Overmolded Inner (Front) Wear Plate (8M0072979)\u003c\/li\u003e\n  \u003cli\u003e1 x Outer Wear Plate with Seal (8M0114788)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n    \u003cli\u003eBefore starting, disconnect the boat's battery and close the engine's water inlet seacock.\u003c\/li\u003e\n    \u003cli\u003eLocate the sea water pump on the engine block. Place a rag or bucket underneath to catch any spilled coolant.\u003c\/li\u003e\n    \u003cli\u003eLoosen the hose clamps and carefully detach the inlet and outlet hoses from the pump housing.\u003c\/li\u003e\n    \u003cli\u003eRemove the bolts securing the pump's front cover or housing plate.\u003c\/li\u003e\n    \u003cli\u003ePry the old impeller out of the housing with pliers. Note the rotational direction of the vanes for reinstallation.\u003c\/li\u003e\n    \u003cli\u003eRemove the old wear plates and seals from the housing and cover. Clean all surfaces thoroughly.\u003c\/li\u003e\n    \u003cli\u003eInstall the new rear and front wear plates from the kit. Ensure they sit flat and are properly aligned.\u003c\/li\u003e\n    \u003cli\u003eLubricate the inside of the pump housing and the new impeller with a water-based marine lubricant or glycerine.\u003c\/li\u003e\n    \u003cli\u003eInstall the new impeller by pushing it into the housing while twisting it in the direction of engine rotation to bend the vanes correctly.\u003c\/li\u003e\n    \u003cli\u003eReinstall the front cover with its new seal\/o-ring, ensuring the bolts are tightened evenly to spec.\u003c\/li\u003e\n    \u003cli\u003eReconnect the water hoses and tighten the clamps securely. Open the seacock.\u003c\/li\u003e\n    \u003cli\u003eReconnect the battery. Start the engine and immediately check the pump and hose connections for leaks. Verify water is exiting the exhaust\/tell-tale.\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 impeller kit fits my MerCruiser engine?\u003c\/summary\u003e\u003cp\u003eFitment for the 4.5L and 6.2L engines is determined by serial number. Please check the 'Engine \u0026amp; Model Compatibility' table and compare the required serial number range with your engine's number. Do not rely on model year alone.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhy is this impeller 0.030\" shorter than the standard one?\u003c\/summary\u003e\u003cp\u003eThis specific impeller is intentionally designed to be slightly shorter for certain MerCruiser sea water pump housings. This design change, paired with the included overmolded wear plates, helps resolve issues of impeller swelling and seizing in some late-model pumps, improving durability and reliability.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat are the signs of a failing sea water pump impeller?\u003c\/summary\u003e\u003cp\u003eCommon symptoms include the engine overheating at idle or low speeds, a weak or non-existent stream of water from the tell-tale outlet, visible cracks or missing vanes on the old impeller upon inspection, and a noticeable decrease in engine cooling performance.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow often should I replace my engine's impeller?\u003c\/summary\u003e\u003cp\u003eAs a general preventative maintenance rule, it is recommended to inspect your sea water pump impeller annually and replace it every 1-2 years or every 100-200 hours of operation, whichever comes first. This interval can be shorter in saltwater or high-debris environments.\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\u003ePro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n  \u003cli\u003eFast Global Fulfillment — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n  \u003cli\u003eManufacturer-Direct Value — 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":50717885727035,"sku":"22KM029","price":57.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_Kit_for_Mercury_47-8M0137221_-_JLM_MARINE-8290047.jpg?v=1762937339","url":"https:\/\/seasierra.com\/products\/heavy-duty-sea-water-pump-impeller-kit-fits-mercury-mercruiser-4-5l-6-2l-mcm-mie-towsport-models-replaces-47-8m0137221","provider":"SeaSierra","version":"1.0","type":"link"}