{"title":"Mercury 4-Stroke Outboard Engine 15-50HP Parts","description":"\u003csection id=\"hero\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003cp\u003eThis page supports Mercury 4‑Stroke 15–50HP outboard engines. Use it to find compatible parts and service information, including maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Mercury collection. Scroll to the bottom of the page to start browsing parts for this engine. On the collection page, use the Filter \u0026amp; Sort controls to narrow results by horsepower, year range, and part category\/section.\u003c\/p\u003e\n  \u003cp\u003e\n    \u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-outboard-parts\" style=\"display:inline-block;padding:10px 16px;border:1px solid #1b4; border-radius:6px; text-decoration:none;\"\u003eBrowse All Mercury Parts\u003c\/a\u003e\n  \u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003ch2\u003eHow to Identify Your 15–50HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the serial\/nameplate on the swivel bracket (port\/starboard side) or near the clamp\/steering tube. The top line is the serial number; a secondary stamp may indicate year.\u003c\/li\u003e\n    \u003cli\u003eModel codes and suffixes indicate features such as shaft length (S\/L\/XL), start type (manual\/electric), control type (tiller\/remote), and gearcase option (standard vs BigFoot).\u003c\/li\u003e\n    \u003cli\u003ePlatform clues: 15–20HP are typically inline‑2 four‑strokes; 25–50HP are commonly inline‑3 four‑strokes. Many 40–50HP units use EFI; some earlier\/smaller models may be carbureted.\u003c\/li\u003e\n    \u003cli\u003eBigFoot (Command Thrust) models have a larger gearcase and propeller for better thrust. Verify this before ordering propellers, gearcase seals, or water pump kits.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003ch2\u003ePlatform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003e15–20HP FourStroke (Portable)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline‑2 four‑stroke, manual or electric start, tiller or remote options.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003eMercury 15HP and 20HP FourStroke portable models (short\/long shaft variants).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eLightweight, quiet operation, excellent trolling economy.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eConfirm pull‑start vs electric‑start parts, and shaft length before ordering controls, cables, or propellers.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003e25–30HP FourStroke (Midrange)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline‑3 four‑stroke, carbureted or EFI depending on year; remote or tiller.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003eMercury 25HP and 30HP FourStroke models; many parts shared across the two outputs.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eStrong mid‑range torque, smooth operation, broad parts availability.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eEFI units require specific high‑pressure fuel filters; verify EFI vs carb before ordering fuel components.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003e40–50HP FourStroke (EFI\/BigFoot Options)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline‑3 EFI four‑stroke on most later models; BigFoot\/Command Thrust gearcase available for heavy loads.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003eMercury 40HP and 50HP FourStroke (standard and BigFoot). Many 50HP engines are EFI.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eGood fuel economy, reliable EFI starting, strong thrust with BigFoot for pontoons and workboats.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003ePropellers, gear ratios, and water pump kits can differ between standard and BigFoot gearcases—confirm before purchase.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"service-kits\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines for Mercury four‑stroke outboards in the 15–50HP class. Always follow the service schedule and specifications in your official Mercury manual for your exact serial range.\u003c\/p\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eEngine oil \u0026amp; filter\u003c\/td\u003e\n        \u003ctd\u003eEvery 100 hours or annually (after break‑in)\u003c\/td\u003e\n        \u003ctd\u003eWarm engine before draining; replace crush washer; verify oil weight per manual.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/oil-filters\"\u003eOil Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd\u003eInspect for water intrusion (milky oil) and metal; replace drain\/fill gaskets.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-lower-unit-seal-kits\"\u003eMercury Lower Unit Seal Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd\u003eInspect 100 hours; replace 200–300 hours or as needed\u003c\/td\u003e\n        \u003ctd\u003eCheck gap and insulator color; misfire under load often indicates worn plugs.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plugs\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eFuel filter \/ water‑separating filter\u003c\/td\u003e\n        \u003ctd\u003eInspect every 50–100 hours; replace annually\u003c\/td\u003e\n        \u003ctd\u003eEFI models require the correct high‑pressure filter; replace bowl gaskets if equipped.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd\u003eEvery 2–3 seasons or 200 hours (inspect annually)\u003c\/td\u003e\n        \u003ctd\u003eEssential for cooling; more frequent service for sandy\/silty use or weak tell‑tale.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-water-pump-repair-kits\"\u003eMercury Water Pump Repair Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAnodes (zinc\/aluminum\/magnesium)\u003c\/td\u003e\n        \u003ctd\u003eInspect every 50 hours; replace when 50% consumed\u003c\/td\u003e\n        \u003ctd\u003eChoose alloy for your water type (salt\/brackish\/fresh). Keep paint off anodes.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service – \u003ca href=\"https:\/\/seasierra.com\/collections\/service-maintenance-kits\"\u003eService \u0026amp; Maintenance Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System – \u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-water-pump-repair-kits\"\u003eMercury Water Pump Repair Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase Seals – \u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-lower-unit-seal-kits\"\u003eMercury Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eFuel System – \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eIgnition \/ Electrical – \u003ca href=\"https:\/\/seasierra.com\/collections\/electrical-items\"\u003eElectrical Items\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropulsion – \u003ca href=\"https:\/\/seasierra.com\/collections\/propellers\"\u003ePropellers\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection – \u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eWeak tell‑tale or overheat alarm\u003c\/td\u003e\n        \u003ctd\u003eClear intake screens; inspect tell‑tale hose; verify impeller condition and thermostat operation.\u003c\/td\u003e\n        \u003ctd\u003eWater pump repair kit, intake screen, thermostat, gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003ePoor acceleration \/ power loss\u003c\/td\u003e\n        \u003ctd\u003eCheck prop damage\/cavitation; replace fuel filter; verify fresh plugs; confirm throttle opening and EFI sensors.\u003c\/td\u003e\n        \u003ctd\u003ePropeller, fuel filter, spark plugs, air\/fuel filters, EFI components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd\u003ePrime fuel system; confirm clean fuel; test plugs; inspect IAC\/idle system (EFI) and vacuum leaks.\u003c\/td\u003e\n        \u003ctd\u003eSpark plugs, fuel filter, injectors (EFI), intake gaskets, primer bulb\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCharging system not working\u003c\/td\u003e\n        \u003ctd\u003eMeasure battery voltage; check fuses and connections; test rectifier\/regulator output.\u003c\/td\u003e\n        \u003ctd\u003eRectifier\/regulator, wiring, battery leads, fuses\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd\u003eDrain and inspect oil; look for water intrusion; check prop shaft seal and drain\/fill plug gaskets.\u003c\/td\u003e\n        \u003ctd\u003eLower unit seal kit, bearings, drain\/fill gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"faq\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable across different years or BigFoot vs standard models?\u003c\/summary\u003e\n    \u003cp\u003eSome components interchange within the same platform and serial range, but key items (propellers, gearcase seals, water pump kits) can differ between standard and BigFoot gearcases and across EFI\/carb model years. Verify by serial number and model suffix before ordering.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the water pump impeller?\u003c\/summary\u003e\n    \u003cp\u003eInspect annually and replace every 2–3 seasons or about 200 hours. Replace sooner if you operate in sandy\/silty water, see a weak tell‑tale, or after an overheat event.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should I change lower‑unit gear oil?\u003c\/summary\u003e\n    \u003cp\u003eChange every 100 hours or annually, and any time you observe water contamination or metal particles. Always replace drain\/fill plug gaskets.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do you need to confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003ePlease provide the engine serial number, model code\/suffix (shaft length, tiller\/remote, BigFoot\/standard), approximate year, and whether the engine is EFI or carbureted.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"max-width:1100px;padding:12px 0;\"\u003e\n  \u003cp\u003eReady to find parts for your Mercury FourStroke 15–50HP? Browse the main Mercury collection by horsepower, year, and model to quickly locate compatible components.\u003c\/p\u003e\n  \u003cp\u003e\n    \u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-outboard-parts\" style=\"display:inline-block;padding:10px 16px;border:1px solid #1b4; border-radius:6px; text-decoration:none;\"\u003eShop Mercury Outboard Parts\u003c\/a\u003e\n  \u003c\/p\u003e\n  \u003cp style=\"font-size:0.95em;color:#333;\"\u003eIf you’re unsure about your model, send us a photo of the nameplate and the part you need and we’ll help verify compatibility.\u003c\/p\u003e\n\u003c\/section\u003e","products":[{"product_id":"water-pump-impeller-fits-mercury-mariner-15-50-hp-replaces-47-8508910-0755466","title":"Water Pump Impeller with Drive Key – Mercury\/Mariner 2-Stroke 15–30 HP \u0026 4-Stroke 8–50 HP","description":"\u003csection\u003e\n\u003cstyle\u003e\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td { padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top; }\n  table.ss-table th { white-space:nowrap; word-break:normal; letter-spacing:normal; font-weight:600; background:#f8fafc; }\n  @media (max-width:480px){ table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; } }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis aftermarket \u003cstrong\u003ewater pump impeller with drive key\u003c\/strong\u003e is designed for selected Mercury and Mariner outboards. It is listed for 2-stroke 15–30 HP applications and specific 4-stroke models from 8 HP through 50 HP. The impeller helps maintain the engine cooling-water flow when installed in a matching water-pump assembly.\u003c\/p\u003e\n\u003cp\u003eThis replacement is cross-referenced to Mercury manufacturer part numbers \u003cstrong\u003e47-85089-3\u003c\/strong\u003e, \u003cstrong\u003e47-85089-10\u003c\/strong\u003e, \u003cstrong\u003e47-85089\u003c\/strong\u003e, and \u003cstrong\u003e47-8508910\u003c\/strong\u003e. The aftermarket reference is \u003cstrong\u003eSierra 18-3057\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAftermarket water pump impeller for selected Mercury and Mariner outboards.\u003c\/li\u003e\n  \u003cli\u003eIncludes one drive key for the listed application.\u003c\/li\u003e\n  \u003cli\u003eVerify the engine model, horsepower, stroke, and original impeller number before ordering.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse the following references to compare the replacement with the number on your original impeller or service parts documentation.\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\u003ctr\u003e\n\u003cth\u003eReference type\u003c\/th\u003e\n\u003cth\u003ePart number\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury manufacturer reference\u003c\/td\u003e\n\u003ctd\u003e47-85089-3\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury manufacturer reference\u003c\/td\u003e\n\u003ctd\u003e47-85089-10\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury manufacturer reference\u003c\/td\u003e\n\u003ctd\u003e47-85089\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury manufacturer reference\u003c\/td\u003e\n\u003ctd\u003e47-8508910\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra aftermarket reference\u003c\/td\u003e\n\u003ctd\u003e18-3057\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\u003eCompany fitment data covers the following Mercury and Mariner application groups. Model, year, serial number, and stroke conditions must be checked together against the engine manufacturer's parts information.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Mercury and Mariner Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eRated horsepower\u003c\/th\u003e\n\u003cth\u003eListed model or application\u003c\/th\u003e\n\u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e15–30 HP\u003c\/td\u003e\n\u003ctd\u003eSelected 15–30 HP applications\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e8 HP\u003c\/td\u003e\n\u003ctd\u003eBodensee, international model\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e9.9 HP\u003c\/td\u003e\n\u003ctd\u003e323 cc model\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e13.5 HP\u003c\/td\u003e\n\u003ctd\u003eInternational model\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e15 HP\u003c\/td\u003e\n\u003ctd\u003eSelected 15 HP applications\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e25 HP\u003c\/td\u003e\n\u003ctd\u003eSelected 25 HP applications\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e30 HP\u003c\/td\u003e\n\u003ctd\u003eSelected 30 HP applications\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e30 HP\u003c\/td\u003e\n\u003ctd\u003eEFI, 3-cylinder\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e40 HP\u003c\/td\u003e\n\u003ctd\u003eSelected 40 HP applications\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e40 HP\u003c\/td\u003e\n\u003ctd\u003eCarbureted, 3-cylinder\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e40 HP\u003c\/td\u003e\n\u003ctd\u003eEFI, 3-cylinder\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e40 HP\u003c\/td\u003e\n\u003ctd\u003eItaly-market model\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e45 HP\u003c\/td\u003e\n\u003ctd\u003eBodensee model\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e50 HP\u003c\/td\u003e\n\u003ctd\u003e50 and Bigfoot applications\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct type\u003c\/dt\u003e\n  \u003cdd\u003eAftermarket water pump impeller with drive key\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eSelected Mercury and Mariner 2-stroke and 4-stroke outboards\u003c\/dd\u003e\n  \u003cdt\u003e2-stroke fitment range\u003c\/dt\u003e\n  \u003cdd\u003e15–30 HP applications listed by the company catalog\u003c\/dd\u003e\n  \u003cdt\u003e4-stroke fitment range\u003c\/dt\u003e\n  \u003cdd\u003eSpecific 8–50 HP applications listed by the company catalog\u003c\/dd\u003e\n  \u003cdt\u003eAftermarket reference\u003c\/dt\u003e\n  \u003cdd\u003eSierra 18-3057\u003c\/dd\u003e\n  \u003cdt\u003eIncluded drive key\u003c\/dt\u003e\n  \u003cdd\u003eYes\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 Drive key\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eConfirm the engine model, horsepower, stroke, serial range, and original impeller reference before beginning work.\u003c\/li\u003e\n  \u003cli\u003eDisconnect the battery and follow the engine manufacturer's service procedure for removing the lower unit.\u003c\/li\u003e\n  \u003cli\u003eLocate the water-pump housing and remove its cover.\u003c\/li\u003e\n  \u003cli\u003eRemove the old impeller and retain the drive key only if it is being replaced or reused according to the service instructions.\u003c\/li\u003e\n  \u003cli\u003eClean the housing and inspect the cover, wear surfaces, seals, and drive-shaft keyway for damage or excessive wear.\u003c\/li\u003e\n  \u003cli\u003eInstall the supplied drive key in the shaft keyway and fit the new impeller, aligning the hub with the key.\u003c\/li\u003e\n  \u003cli\u003eReassemble the water-pump housing and lower unit using the manufacturer's torque sequence and sealing requirements.\u003c\/li\u003e\n  \u003cli\u003eTest the engine with an appropriate water supply and confirm normal cooling-water flow before operating the boat.\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 fitment?\u003c\/summary\u003e\n  \u003cp\u003eCompare your original impeller number with the Part Number Matrix, then confirm the engine brand, exact model, horsepower, stroke, year, and serial number. A horsepower-only match is not sufficient because water-pump designs can vary within the same horsepower range.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are common signs of a worn impeller?\u003c\/summary\u003e\n  \u003cp\u003ePossible signs include weak or missing telltale water flow, overheating warnings, reduced cooling performance, damaged vanes, cracks, or a visibly hardened impeller. Inspect the complete water-pump assembly when replacing the impeller.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDoes this product include the drive key?\u003c\/summary\u003e\n  \u003cp\u003eYes. This product is listed by the company catalog as an impeller with key and includes one drive key.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM part?\u003c\/summary\u003e\n  \u003cp\u003eNo. This is an aftermarket replacement. The manufacturer references shown on this page are provided for application and part-number comparison only.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eShould I replace the water-pump housing at the same time?\u003c\/summary\u003e\n  \u003cp\u003eInspect the housing, cover, wear surfaces, seals, and keyway during installation. Replace any worn or damaged components according to the engine manufacturer's service instructions.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eFitment is limited to the listed Mercury and Mariner application groups; do not rely on horsepower alone.\u003c\/li\u003e\n  \u003cli\u003eCheck the original part number and compare the replacement's hub and overall dimensions before installation.\u003c\/li\u003e\n  \u003cli\u003eFollow the engine manufacturer's service manual for lower-unit removal, torque values, sealing compounds, and testing procedures.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement and is not manufactured by Mercury, Mariner, or Sierra.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended if you are not familiar with outboard lower-unit service.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMarine replacement parts\u003c\/strong\u003e — Practical aftermarket components for routine service and repair.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication-focused listings\u003c\/strong\u003e — Product references and fitment details are provided to help match the correct part.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eService-minded support\u003c\/strong\u003e — Contact support with your engine model and serial number when additional fitment information is needed.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723786162491,"sku":"17IM007-K","price":17.38,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_for_Mercury_15-50_HP__18-3057_-_JLM_MARINE-8288073.jpg?v=1763031717"},{"product_id":"water-pump-impeller-fits-mercury-mariner-15-50-hp-replaces-47-8508910","title":"Water Pump Impeller for Mercury\/Mariner 2-Stroke 15–30 HP and Select 4-Stroke Models","description":"\u003csection\u003e\n\u003cstyle\u003e\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td { padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top; }\n  table.ss-table th { white-space:nowrap; word-break:normal; letter-spacing:normal; font-weight:600; background:#f8fafc; }\n  @media (max-width:480px){ table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; } }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis aftermarket \u003cstrong\u003ewater pump impeller\u003c\/strong\u003e is designed for specified Mercury and Mariner outboard applications. The company fitment records identify this impeller for Mercury\/Mariner 2-stroke 15–30 HP engines and the listed 4-stroke models below. It is intended as a direct replacement for the original water-pump impeller when the engine, model, stroke type, and part-number reference match.\u003c\/p\u003e\n\u003cp\u003eThe primary replacement references documented for this impeller are Mercury part numbers \u003cstrong\u003e47-85089-3\u003c\/strong\u003e, \u003cstrong\u003e47-85089-10\u003c\/strong\u003e, \u003cstrong\u003e47-85089\u003c\/strong\u003e, and \u003cstrong\u003e47-8508910\u003c\/strong\u003e. Sierra \u003cstrong\u003e18-3057\u003c\/strong\u003e and Mallory \u003cstrong\u003e9-45303\u003c\/strong\u003e are listed as aftermarket reference numbers.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSingle aftermarket water pump impeller; not a complete repair kit.\u003c\/li\u003e\n  \u003cli\u003eDesigned for the specified Mercury and Mariner 2-stroke and 4-stroke applications.\u003c\/li\u003e\n  \u003cli\u003eHigh-volume, long-vane impeller configuration associated with the documented 47-85089-10 reference.\u003c\/li\u003e\n  \u003cli\u003eConfirm the original impeller, engine model, stroke type, and part number before ordering.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse these references for identification and cross-checking. Number listings are reference information and do not replace confirmation of the complete engine application.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n    \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eBrand or Source\u003c\/th\u003e\n\u003cth\u003eReference Number\u003c\/th\u003e\n\u003cth\u003eRole\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-85089-3\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-85089-10\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-85089\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e47-8508910\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3057\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory\u003c\/td\u003e\n\u003ctd\u003e9-45303\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference\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\u003eThe company fitment records cover the following application groups. For the 2-stroke range, verify the exact engine model and serial-number range because the supplied company data identifies the range by horsepower only.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Mercury and Mariner Engine Compatibility\"\u003e\n    \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eApplication\u003c\/th\u003e\n\u003cth\u003eModel or Description\u003c\/th\u003e\n\u003cth\u003eFitment Note\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e15–30 HP\u003c\/td\u003e\n\u003ctd\u003eSpecified 2-stroke outboards\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model and serial number.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e8 HP\u003c\/td\u003e\n\u003ctd\u003eBodensee; internal application listing\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e9.9 HP\u003c\/td\u003e\n\u003ctd\u003e323 cc\u003c\/td\u003e\n\u003ctd\u003eInternational or model-specific application; confirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e13.5 HP\u003c\/td\u003e\n\u003ctd\u003eInternational\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e15 HP\u003c\/td\u003e\n\u003ctd\u003eSpecified 4-stroke model\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e25 HP\u003c\/td\u003e\n\u003ctd\u003eSpecified 4-stroke model\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e30 HP\u003c\/td\u003e\n\u003ctd\u003eStandard and 3-cylinder EFI applications\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e40 HP\u003c\/td\u003e\n\u003ctd\u003eStandard, 3-cylinder carbureted, Italy, and specified 3-cylinder EFI applications\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e45 HP\u003c\/td\u003e\n\u003ctd\u003eBodensee\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e50 HP\u003c\/td\u003e\n\u003ctd\u003eStandard and Bigfoot\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model.\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n\u003cdd\u003eWater pump impeller\u003c\/dd\u003e\n  \u003cdt\u003eProduct Configuration\u003c\/dt\u003e\n\u003cdd\u003eSingle impeller\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n\u003cdd\u003eMercury \/ Mariner outboard cooling systems\u003c\/dd\u003e\n  \u003cdt\u003eVane Configuration\u003c\/dt\u003e\n\u003cdd\u003eHigh-volume, long-vane design\u003c\/dd\u003e\n  \u003cdt\u003eOutside Diameter\u003c\/dt\u003e\n\u003cdd\u003eApproximately 73.0 mm (2.875 in)\u003c\/dd\u003e\n  \u003cdt\u003eInside Diameter\u003c\/dt\u003e\n\u003cdd\u003eApproximately 16.0 mm (0.625 in)\u003c\/dd\u003e\n  \u003cdt\u003eHeight\u003c\/dt\u003e\n\u003cdd\u003eApproximately 12.6 mm\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\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e The company record identifies this product as a single impeller, not a kit. A key, gasket, washers, O-rings, wear plate, and other water-pump service parts are not included unless separately stated in the order details.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eVerify the engine model, stroke type, serial number, and original impeller reference before beginning work.\u003c\/li\u003e\n  \u003cli\u003eDisconnect the battery and follow the outboard manufacturer’s service procedure for removing the lower unit.\u003c\/li\u003e\n  \u003cli\u003eRemove the water-pump housing and take out the old impeller.\u003c\/li\u003e\n  \u003cli\u003eInspect the housing, wear plate, keyway, gaskets, O-rings, and related components for wear or damage. Replace service parts as required.\u003c\/li\u003e\n  \u003cli\u003eClean the housing and mating surfaces before installing the replacement impeller.\u003c\/li\u003e\n  \u003cli\u003eInstall the impeller using the correct key and orient the vanes in the direction specified by the engine manufacturer.\u003c\/li\u003e\n  \u003cli\u003eReassemble the water pump and lower unit using the manufacturer’s torque specifications.\u003c\/li\u003e\n  \u003cli\u003eRun the engine according to the manufacturer’s testing procedure and confirm proper cooling-water flow before normal operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eMaintenance \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I confirm that this impeller fits my engine?\u003c\/summary\u003e\n  \u003cp\u003eMatch your engine brand, horsepower, stroke type, exact model, and serial number to the compatibility information. Also compare the original impeller and its manufacturer reference with the documented references, including Mercury 47-85089-3 or 47-85089-10 and Sierra 18-3057.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this a complete water-pump kit?\u003c\/summary\u003e\n  \u003cp\u003eNo. This product is a single aftermarket water pump impeller. It does not include a key, gasket, washers, O-rings, wear plate, housing, or other repair-kit components.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are the signs of a worn water-pump impeller?\u003c\/summary\u003e\n  \u003cp\u003ePossible signs include weak cooling-water flow, overheating warnings, or overheating during operation. Inspect the complete cooling system because water-flow problems can have causes other than the impeller.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eShould the key and gaskets be replaced at the same time?\u003c\/summary\u003e\n  \u003cp\u003eInspect the key, housing, wear plate, gaskets, and O-rings during service. Replace any worn, damaged, hardened, or distorted components with parts appropriate for the specific engine.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM component?\u003c\/summary\u003e\n  \u003cp\u003eNo. This is an aftermarket replacement impeller. The OEM and aftermarket numbers shown on this page are reference numbers for identification only.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eDo not rely on horsepower alone. Confirm the exact model, stroke type, serial number, and original part number.\u003c\/li\u003e\n  \u003cli\u003eDo not install this impeller if its dimensions, keyway, vane configuration, or reference markings differ from the original part without professional verification.\u003c\/li\u003e\n  \u003cli\u003eFollow the outboard manufacturer’s service manual and torque specifications.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended when lower-unit or water-pump service is unfamiliar.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMarine Replacement Parts\u003c\/strong\u003e — Practical aftermarket components for routine marine maintenance and repair.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Product references and fitment information are provided to support careful part identification.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCustomer Support\u003c\/strong\u003e — Contact support with your engine model, serial number, and original part information when application assistance is needed.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723786228027,"sku":"17IM007","price":15.18,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_for_Mercury_15-50_HP_47-8508910_-_0755466_-_JLM_MARINE-8289726.jpg?v=1763031719"}],"url":"https:\/\/seasierra.com\/collections\/mercury-4-stroke-outboard-engine-15-50hp-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}