{"title":"Yamaha 2-Stroke 20-50HP Outboard Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px 0;\"\u003e\n  \u003cp\u003eThis page covers Yamaha 2-Stroke 20-50HP outboard engines and helps you quickly find compatible parts and service information. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Yamaha outboard collection any time. Scroll to the bottom of this page to start browsing parts for this engine, and on the collection page use the Filter \u0026amp; Sort controls to narrow results by horsepower, year range, and part category.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\" style=\"display:inline-block;padding:10px 16px;background:#004a7c;color:#fff;text-decoration:none;border-radius:4px;\"\u003eBrowse All Yamaha Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"padding:12px 0;\"\u003e\n  \u003ch2\u003eHow to Identify Your 20-50HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eFind the engine ID plate on the transom bracket or swivel bracket. It lists the model code, serial number, and sometimes the production date.\u003c\/li\u003e\n    \u003cli\u003eRead the model code and suffix: the letters often indicate shaft length (e.g., S\/L\/X), control type (tiller vs. remote), and other options; the suffix can correspond to a year or revision.\u003c\/li\u003e\n    \u003cli\u003eConfirm platform: 20–25HP models are typically 2-cylinder; 30–50HP models are commonly 3-cylinder 2‑strokes. Counting plug leads\/carburetors can help distinguish them.\u003c\/li\u003e\n    \u003cli\u003eDetermine oiling: Many Yamaha 2‑strokes use oil injection, while others are premix. Verify your system type and follow the service manual for the correct oil ratio and procedures.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"platforms\" style=\"padding:12px 0;\"\u003e\n  \u003ch2\u003eEngine\/Platform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003e20–25HP Class\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;max-width:900px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInline‑2, carbureted 2‑stroke\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e20HP–25HP 2‑stroke variants (tiller or remote, short\/long shaft)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eLightweight, easy to service, strong low‑speed thrust for small craft\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eVerify whether your engine uses oil injection or premix; ignition and carburetor parts differ by year and control type.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003e30–50HP Class\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;max-width:900px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInline‑3, loop‑charged carbureted 2‑stroke\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e30HP, 40HP, and 50HP 2‑stroke variants (electric\/manual start; remote\/tiller)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eGood power‑to‑weight, strong mid‑range, simple mechanical systems\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003ePropeller pitch and gearcase ratios vary; match prop to hull and load. Use model\/serial to confirm ignition, carb, and gearcase parts.\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=\"padding:12px 0;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines; always follow the procedures and schedules in your official Yamaha service manual.\u003c\/p\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;max-width:900px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInspect for water intrusion or metal shavings; replace drain gaskets\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-service-maintenance-kits\"\u003eYamaha Service \u0026amp; Maintenance Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInspect every 50 hours; replace as needed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCheck gap and color; fouling often indicates rich mix or idle issues\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\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 style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eFuel filter \/ inline filter\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eReplace sooner if contaminated fuel or storage use is common\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\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 style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEvery season or 100 hours\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEssential for cooling; replace more often in sandy or shallow use\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-water-pump-repair-kits\"\u003eYamaha Water Pump Repair Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAnodes (internal\/external)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInspect every 50 hours; replace when 50% gone\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eUse correct material for fresh, brackish, or salt water\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-anodes\"\u003eYamaha Anodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eOil injection system check (if equipped)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eVerify pump operation, lines, and tank; bleed per manual if serviced\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\"\u003eYamaha Outboard Parts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eFuel\/oil premix (for premix models)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEvery fill‑up\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eFollow the model‑specific ratio in the service\/owner’s manual\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\"\u003eYamaha Outboard Parts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n  \u003cp style=\"font-size:12px;color:#666;\"\u003e*Intervals are general guidelines and may vary by model\/year and operating conditions. Always consult your official Yamaha manual.\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"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\/yamaha-service-maintenance-kits\"\u003eYamaha Service \u0026amp; Maintenance Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-water-pump-repair-kits\"\u003eYamaha Water Pump Repair Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase \u0026amp; Seals – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-lower-unit-seal-kits\"\u003eYamaha Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropellers – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-propellers\"\u003eYamaha Propellers\u003c\/a\u003e | Protection – \u003ca href=\"https:\/\/seasierra.com\/collections\/propeller-guards\"\u003ePropeller Guards\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\u003eFuel System – \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e \u0026amp; \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-pumps\"\u003eFuel Pumps\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-anodes\"\u003eYamaha Anodes\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"padding:12px 0;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;max-width:900px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eWeak tell‑tale stream or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInspect intake screens for debris; verify impeller condition; confirm thermostat operation\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eWater pump kit, thermostat, intake screen\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003ePoor acceleration \/ power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCheck fuel quality and filters; inspect spark plugs; verify prop condition and pitch match\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eFuel filter, spark plugs, propeller\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003ePrime fuel system; confirm choke\/enrichment; clean\/adjust idle mixture; compression test if needed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eSpark plugs, inline fuel filter, carburetor cleaning\/rebuild components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eExcessive smoke (2‑stroke)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eConfirm correct premix ratio or oil‑injection setting; ensure thermostat closes properly; verify idle mixture\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eSpark plugs, oil injection hoses\/tank components, thermostat\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCheck gear oil level\/condition; inspect prop shaft seals and fishing line damage\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eLower unit seal kit, gear lube, prop shaft bearings\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=\"padding:12px 0;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable between different years or platforms?\u003c\/summary\u003e\n    \u003cp\u003eNot always. Even within 20–50HP, ignition, carburetion, and gearcase components can vary by year, shaft length, and control type. Use your full model code and serial number to confirm fitment.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should the impeller be replaced?\u003c\/summary\u003e\n    \u003cp\u003eAs a rule, every season or 100 hours, and sooner if you operate in sandy, silty, or shallow conditions. A weak tell‑tale or rising temperatures are signs to service the pump immediately.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should lower unit gear oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eChange gear oil at least annually or every 100 hours. Inspect for water (milky oil) or metal. Replace drain screw gaskets each service.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information helps confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide the model code, serial number, horsepower, shaft length (S\/L\/X), starting method (manual\/electric), and control type (tiller\/remote). Photos of the ID plate and the part you’re replacing are also helpful.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"padding:16px 0;\"\u003e\n  \u003cp\u003eReady to find parts by horsepower, year, and model? Browse the Yamaha outboard collection and refine with Filter \u0026amp; Sort to get the exact components for your engine.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\" style=\"display:inline-block;padding:10px 16px;background:#004a7c;color:#fff;text-decoration:none;border-radius:4px;\"\u003eShop Yamaha Outboard Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px;font-size:12px;color:#555;\"\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-yamaha-20hp-50hp-outboards-replaces-6h4-44352-00-6h4-44352-01-6h4-44352-02","title":"Water Pump Impeller for Yamaha 2-Stroke and 4-Stroke Outboards – Replaces 6H4-44352-00, 6H4-44352-01 and 6H4-44352-02","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 replacement \u003cstrong\u003ewater pump impeller\u003c\/strong\u003e is listed for selected Yamaha outboards with both 2-stroke and 4-stroke configurations. It is supplied as a single impeller for replacing a worn or damaged water-pump impeller and helping restore the cooling-water flow required for normal engine operation.\u003c\/p\u003e\n\u003cp\u003eThe impeller is listed for Yamaha OEM references \u003cstrong\u003e6H4-44352-00-00\u003c\/strong\u003e, \u003cstrong\u003e6H4-44352-01-00\u003c\/strong\u003e, and \u003cstrong\u003e6H4-44352-02-00\u003c\/strong\u003e. Related aftermarket references listed for this product include \u003cstrong\u003eSierra 18-3068\u003c\/strong\u003e and \u003cstrong\u003eMallory 9-45601\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplacement water pump impeller for selected Yamaha outboards.\u003c\/li\u003e\n  \u003cli\u003eApplicable fitment is separated by engine model and stroke type below.\u003c\/li\u003e\n  \u003cli\u003eImpeller only; the installation key is not included.\u003c\/li\u003e\n  \u003cli\u003eConfirm the complete engine model and existing impeller 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 impeller with your original part. Part-number listings are reference identifiers and should be checked against the exact engine model.\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\u003c\/th\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003cth\u003eReference\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-44352-00-00\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-44352-01-00\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-44352-02-00\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra Marine\u003c\/td\u003e\n\u003ctd\u003e18-3068\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory Marine\u003c\/td\u003e\n\u003ctd\u003e9-45601\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 data lists the following Yamaha model codes. The 2-stroke and 4-stroke applications are kept separate because model and stroke conditions must match your engine exactly.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine and Model Compatibility\"\u003e\n    \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eModel Codes\u003c\/th\u003e\n\u003cth\u003eRated HP Range\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eOEM References\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha Outboard\u003c\/td\u003e\n        \u003ctd\u003e25B, 25J, 25N, 25Q, 25V, 25XMH, 30D, 30G, 30H, 40H, 40X, 50D\u003c\/td\u003e\n        \u003ctd\u003e25–50 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e6H4-44352-00-00, 6H4-44352-01-00, 6H4-44352-02-00\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha Outboard\u003c\/td\u003e\n        \u003ctd\u003eF20A, F20D, F25A, FT25B, F25D, FT25F, F30A, F30B, F40B, F40F\u003c\/td\u003e\n        \u003ctd\u003e20–40 HP\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e6H4-44352-00-00, 6H4-44352-01-00, 6H4-44352-02-00\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp\u003eCatalog evidence also shows this impeller reference in selected Yamaha 40 HP and 50 HP 2-stroke applications, including model-year examples from 1984–1986. This does not expand the company fitment list; verify the exact model code, year, and serial-number range for your engine before installation.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eWater pump impeller\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eSelected Yamaha 2-stroke and 4-stroke outboards\u003c\/dd\u003e\n  \u003cdt\u003eOEM References\u003c\/dt\u003e\n  \u003cdd\u003e6H4-44352-00-00, 6H4-44352-01-00, 6H4-44352-02-00\u003c\/dd\u003e\n  \u003cdt\u003eAftermarket References\u003c\/dt\u003e\n  \u003cdd\u003eSierra 18-3068; Mallory 9-45601\u003c\/dd\u003e\n  \u003cdt\u003eInstallation Key\u003c\/dt\u003e\n  \u003cdd\u003eNot included; verify the required key against the engine and pump assembly\u003c\/dd\u003e\n  \u003cdt\u003eReplacement Type\u003c\/dt\u003e\n  \u003cdd\u003eAftermarket replacement impeller\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\u003eNot included:\u003c\/strong\u003e installation key, gaskets, water-pump housing, wear plate, bolts, seals, or other water-pump components.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the battery and place the outboard in neutral.\u003c\/li\u003e\n  \u003cli\u003eRemove the lower unit according to the engine manufacturer’s service procedure.\u003c\/li\u003e\n  \u003cli\u003eRemove the water-pump housing and inspect the housing, wear plate, seals, and related components for wear or damage.\u003c\/li\u003e\n  \u003cli\u003eRemove the old impeller and the existing shaft key. Do not reuse a damaged or distorted key.\u003c\/li\u003e\n  \u003cli\u003eVerify the replacement key and pump components for your exact engine before assembly; the key is not included with this impeller.\u003c\/li\u003e\n  \u003cli\u003eInstall the impeller on the driveshaft, aligning the keyway with the shaft key.\u003c\/li\u003e\n  \u003cli\u003eReinstall the water-pump housing while turning the driveshaft in the correct direction for the engine so the vanes seat properly.\u003c\/li\u003e\n  \u003cli\u003eReinstall the lower unit, reconnect the battery, and complete any required gearcase-fluid service.\u003c\/li\u003e\n  \u003cli\u003eRun the engine using the manufacturer’s procedure and confirm a strong, consistent tell-tale stream. Stop the engine immediately if the stream is weak or absent.\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 compatibility?\u003c\/summary\u003e\n  \u003cp\u003eMatch the complete engine model code and stroke type with the compatibility table. Do not rely only on horsepower. Year and serial-number conditions may also affect fitment, so compare your original impeller and verify the applicable service information before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are signs of a worn water pump impeller?\u003c\/summary\u003e\n  \u003cp\u003eCommon signs include overheating, a weak or intermittent tell-tale stream, reduced cooling-water flow, or visible damage to the impeller, pump housing, or wear plate. Continued operation with inadequate cooling can cause serious engine damage.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDoes this impeller include the installation key?\u003c\/summary\u003e\n  \u003cp\u003eNo. This listing is for one impeller only. The installation key is not included and must be verified or purchased separately for the exact engine and water-pump assembly.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eCan I use the old gasket or water-pump housing?\u003c\/summary\u003e\n  \u003cp\u003eInspect all related water-pump components during installation. Replace worn, damaged, hardened, or distorted gaskets, seals, housing parts, or wear plates as required by the engine manufacturer’s service procedure.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhy is the tell-tale stream weak after installation?\u003c\/summary\u003e\n  \u003cp\u003ePossible causes include incorrect vane orientation, a missing or improperly seated key, a blocked tell-tale outlet or cooling passage, a worn pump housing, damaged seals, or an engine application mismatch. Recheck the installation and confirm the exact model fitment before operating the engine further.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM Yamaha part?\u003c\/summary\u003e\n  \u003cp\u003eNo. This is an aftermarket replacement impeller listed against the Yamaha OEM references shown above. Yamaha, Sierra, and Mallory are referenced only for identification and compatibility purposes.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should the impeller be replaced?\u003c\/summary\u003e\n  \u003cp\u003eReplacement intervals depend on the engine manufacturer’s maintenance schedule and operating conditions. Inspect the impeller regularly and replace it when the service interval is reached or whenever it shows cracking, hardening, damaged vanes, deformation, or other wear.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify the complete engine model, stroke type, year, and serial-number range before ordering.\u003c\/li\u003e\n  \u003cli\u003eCompare the original impeller, keyway, and pump components with the product required for your engine.\u003c\/li\u003e\n  \u003cli\u003eThis product is an aftermarket replacement, not an OEM Yamaha component.\u003c\/li\u003e\n  \u003cli\u003eUse appropriate service information and follow safe procedures when removing or installing the lower unit.\u003c\/li\u003e\n  \u003cli\u003eDo not operate the engine if the cooling-water stream is weak, intermittent, or absent.\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 — We provide replacement components for common outboard and marine-system service needs.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFitment-Focused Listings\u003c\/strong\u003e — Product references and model information are provided to help you compare the replacement with your original part.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSupport for Installation Planning\u003c\/strong\u003e — Always confirm the complete engine application and required related hardware before beginning service.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723798352187,"sku":"17IY007","price":15.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_for_Yamaha_F40_-_F50_-_F60__6H4-44352-01_-_JLM_MARINE-8288654.jpg?v=1763032063"}],"url":"https:\/\/seasierra.com\/collections\/yamaha-2-stroke-20-50hp-outboard-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}