{"title":"Yamaha 40-50HP 2-Stroke Outboard Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px;border:1px solid #e5e7eb;border-radius:8px;max-width:1100px;margin:0 auto 20px auto\"\u003e\n  \u003cp\u003eThis page is tailored to Yamaha 2‑Stroke 40–50HP outboard engines. Use it to find compatible parts, routine maintenance guidance, common replacement items, and troubleshooting tips. You can also browse the main Yamaha collection. 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;margin-top:8px;padding:10px 14px;background:#0d6efd;color:#fff;text-decoration:none;border-radius:6px\"\u003eBrowse All Yamaha Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"max-width:1100px;margin:0 auto 24px auto\"\u003e\n  \u003ch2\u003eHow to Identify Your 40–50HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the identification plate on the transom bracket or clamp bracket. It lists the model code, shaft length, and serial number.\u003c\/li\u003e\n    \u003cli\u003eReading the code: the two digits indicate horsepower (e.g., 40 or 50). Suffix letters commonly denote shaft length (S=15\", L=20\", X=25\"), control\/trim options, and a year code.\u003c\/li\u003e\n    \u003cli\u003e2‑Stroke specifics: many 40\/50HP models are inline‑3, carbureted. Some families are labeled C40\/C50, P40\/P50, or Pro50. Oil‑injection (Autolube) vs premix can vary by year\/market—verify which system you have.\u003c\/li\u003e\n    \u003cli\u003eIf you’re unsure, photograph the nameplate and the engine mid‑section to help confirm platform, shaft length, and rigging.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"max-width:1100px;margin:0 auto 24px auto\"\u003e\n  \u003ch2\u003ePlatform Overview\u003c\/h2\u003e\n  \u003ch3\u003eYamaha 2‑Stroke 40–50HP (Inline‑3, Carbureted)\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 #e5e7eb;padding:8px\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eInline‑3, carbureted 2‑Stroke; mechanical fuel system; conventional reed induction\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eExamples include C40\/C50, P40\/P50, and Pro50 variants across multiple years\/markets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eLightweight package, strong mid‑range punch, straightforward service procedures\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eCooling and gearcase service items (impeller kits, seals, anodes) are commonly shared across many 40\/50HP inline‑3 families. Verify by model\/serial before ordering.\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;margin:0 auto 24px auto\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines for 2‑Stroke Yamaha outboards. Always follow the official Yamaha service manual for your exact model and duty cycle.\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 #e5e7eb;padding:8px\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eLower unit gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003e100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eInspect for water intrusion\/metal; replace sealing washers and service seals as needed\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-lower-unit-seal-kits\"\u003eYamaha Lower Unit Seal Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003e100 hrs or annually (inspect sooner if misfire\/poor idle)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eGap to spec; read deposits for mixture\/ignition health\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\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:8px;border-bottom:1px solid #f1f5f9\"\u003eFuel filter (inline\/under‑cowl)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003e100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eReplace more often with ethanol fuel or if storage debris is present\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\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:8px;border-bottom:1px solid #f1f5f9\"\u003eWater pump impeller\/kit\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eInspect annually; replace 2–3 years or sooner if weak tell‑tale\/overheat\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eSand\/silt use shortens life; always check housing and wear plate\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\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:8px;border-bottom:1px solid #f1f5f9\"\u003eAnodes (sacrificial)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eInspect every 50–100 hrs; replace when 50% depleted\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eMatch material to water (aluminum for brackish\/fresh; zinc for salt, per spec)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\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:8px;border-bottom:1px solid #f1f5f9\"\u003eCarburetor clean\/sync\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eAs needed (storage, stale fuel, rough idle)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eDrain bowls for storage; balance carbs after service\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/carburetor\"\u003eCarburetor\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eOil‑injection system (if equipped)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eSeasonally\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eVerify pump setting, bleed lines, inspect tanks\/hoses; premix models follow mix ratio\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/hoses\"\u003eHoses\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:#6b7280;margin-top:6px\"\u003e*Follow your model’s service manual for exact schedules, fluids, and procedures.\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"max-width:1100px;margin:0 auto 24px auto\"\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\u003eFuel System – \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/carburetor\"\u003eCarburetor\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eIgnition \/ Electrical – \u003ca href=\"https:\/\/seasierra.com\/collections\/electrical-items\"\u003eElectrical Items\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/starters\"\u003eStarters\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    \u003cli\u003ePropulsion – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-propellers\"\u003eYamaha Propellers\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/propeller-guards\"\u003ePropeller Guards\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase Service – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-lower-unit-seal-kits\"\u003eYamaha Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"max-width:1100px;margin:0 auto 24px auto\"\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 #e5e7eb;padding:8px\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eWeak tell‑tale or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eInspect intake screen for blockage; verify thermostat operation; evaluate impeller and housing wear\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eWater pump kit, thermostat, intake screen\/anode assemblies\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003ePoor acceleration \/ power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eCheck fuel quality, replace inline filter, clean carburetors, verify timing and plug condition\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eFuel filter, carburetor kits, spark plugs\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003ePrime bulb firmness, choke\/enrichment function, carb balance, plug gap\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eFuel line\/primer, carburetor service parts, spark plugs\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eExcessive smoke (2‑Stroke)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eVerify oiling system (Autolube) or premix ratio; confirm thermostat closes; check idle mixture\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eHoses\/tanks for oiling system, thermostat, carburetor needles\/jets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eGearcase noise or metal in oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eDrain oil, inspect for water ingress; pressure\/vacuum test; check prop shaft seals and carrier\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9\"\u003eSeal kits, prop shaft seals, drain\/fill plug 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;margin:0 auto 24px auto\"\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\u003eMany cooling and gearcase items overlap across Yamaha 2‑Stroke 40\/50 inline‑3 families, but ignition, carburetion, and rigging can change by year or sub‑model. Always confirm with your exact model and serial number.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the impeller?\u003c\/summary\u003e\n    \u003cp\u003eInspect annually and replace every 2–3 seasons under normal use. In sandy or shallow environments, replace sooner. A weak tell‑tale, elevated temperatures, or noisy pump housing are signs to service immediately.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should the gear oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eAt least every 100 hours or annually. If the oil appears milky, burnt, or contains metal, service the seals and diagnose the cause before further operation.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do you need to verify part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide the model code, serial number, shaft length, and clear photos of the nameplate and the component you’re replacing. This ensures we match the correct parts to your exact engine.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"padding:16px;border:1px solid #e5e7eb;border-radius:8px;max-width:1100px;margin:0 auto 20px auto\"\u003e\n  \u003cp\u003eReady to find parts for your Yamaha 2‑Stroke 40–50HP? Browse the main Yamaha collection to filter by horsepower, year, and model.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\" style=\"display:inline-block;margin:8px 0;padding:10px 14px;background:#0d6efd;color:#fff;text-decoration:none;border-radius:6px\"\u003eShop Yamaha Outboard Parts\u003c\/a\u003e\n  \u003cp style=\"font-size:12px;color:#6b7280\"\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-service-kit-fits-yamaha-2-stroke-40-50-hp-replaces-6h4-w0078-00-18-3408-18-3429","title":"Water Pump Repair Kit Without Housing – Yamaha 2-Stroke 40\/50 HP (Replaces 6H4-W0078-00-00, 6H4-W0078-A0-00, Sierra 18-3429)","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 {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n  table.ss-table th {\n    white-space:nowrap; word-break:normal; letter-spacing:normal;\n    font-weight:600; background:#f8fafc;\n  }\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eWater Pump Repair Kit Without Housing\u003c\/strong\u003e is an aftermarket service kit for selected Yamaha 2-stroke 40 HP and 50 HP outboard water pumps. It is intended for water-pump service in the lower unit and supplies the wear components needed to renew the pump assembly. The kit does \u003cstrong\u003enot\u003c\/strong\u003e include the water-pump housing.\u003c\/p\u003e\n\u003cp\u003eThe kit is cross-referenced to Yamaha OEM part numbers \u003cstrong\u003e6H4-W0078-00-00\u003c\/strong\u003e and \u003cstrong\u003e6H4-W0078-A0-00\u003c\/strong\u003e, and to Sierra aftermarket number \u003cstrong\u003e18-3429\u003c\/strong\u003e. The related Sierra 18-3408 reference is a water-pump kit with housing and is not listed as an included component of this product.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFor installation in the outboard lower unit water-pump assembly.\u003c\/li\u003e\n\u003cli\u003eIncludes a replacement impeller, key, insert cup, wear plate, gaskets, bolts and water seal.\u003c\/li\u003e\n\u003cli\u003eSupplied without the water-pump housing.\u003c\/li\u003e\n\u003cli\u003eAftermarket replacement kit; not an original Yamaha component.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse the following references together with your engine model, year and serial number to confirm the correct application.\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\u003eBrand\u003c\/th\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003cth\u003eDescription\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-W0078-00-00\u003c\/td\u003e\n\u003ctd\u003eWater pump repair kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-A0-00\u003c\/td\u003e\n\u003ctd\u003eWater pump repair kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-01-00\u003c\/td\u003e\n\u003ctd\u003eCatalog reference appearing on selected Yamaha 40\/50 HP applications; verify the complete engine model before ordering\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3429\u003c\/td\u003e\n\u003ctd\u003eWater pump kit without housing\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\u003eCatalog records associate this water-pump repair-kit family with Yamaha 2-stroke 40 HP and 50 HP outboards, including model-specific applications from the 1980s and early 1990s. Because Yamaha fitment varies by model code and production range, do not rely on horsepower alone.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Compatible Engine Models\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eCatalog application examples\u003c\/th\u003e\n\u003cth\u003eReference\u003c\/th\u003e\n\u003cth\u003eFitment note\u003c\/th\u003e\n\u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e40ELN, 40ESN, 40LN, 40SN (1984); 40ELK and 40ESK (1985)\u003c\/td\u003e\n        \u003ctd\u003e6H4-W0078-00-00\u003c\/td\u003e\n        \u003ctd\u003eExamples from engine catalog records; verify the exact model code and serial range.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e50ETLK, 50ETLN, 50ETSK and 50ETSN (1984)\u003c\/td\u003e\n        \u003ctd\u003e6H4-W0078-00-00\u003c\/td\u003e\n        \u003ctd\u003eExamples from engine catalog records; verify the exact model code and serial range.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eSelected 1992–1993 40 HP models, including 40EJRQ, 40ELRQ, 40ESRQ, 40MJHQ, 40MLHQ, 40MSHQ, 40PLRQ, 40EJRR, 40ELRR, 40ESRR, 40MJHR, 40MLHR, 40MSHR and 40PLRR\u003c\/td\u003e\n        \u003ctd\u003e6H4-W0078-01-00\u003c\/td\u003e\n        \u003ctd\u003eModel-specific catalog lead; confirm the complete model and serial information.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eSelected 1992–1993 50 HP models, including 50EJRQ, 50ELRQ, 50TLHQ, 50EJRR and 50ELRR\u003c\/td\u003e\n        \u003ctd\u003e6H4-W0078-01-00\u003c\/td\u003e\n        \u003ctd\u003eModel-specific catalog lead; confirm the complete model and serial information.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e The application examples above are not a universal year range. Check the engine identification label and compare the complete model code, production year and serial range 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 repair kit without housing\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n\u003cdd\u003eSelected Yamaha 2-stroke 40 HP and 50 HP outboards\u003c\/dd\u003e\n  \u003cdt\u003eInstallation Location\u003c\/dt\u003e\n\u003cdd\u003eLower unit water-pump assembly\u003c\/dd\u003e\n  \u003cdt\u003eImpeller Material\u003c\/dt\u003e\n\u003cdd\u003eNeoprene\u003c\/dd\u003e\n  \u003cdt\u003eHousing Included\u003c\/dt\u003e\n\u003cdd\u003eNo\u003c\/dd\u003e\n  \u003cdt\u003eProduct Status\u003c\/dt\u003e\n\u003cdd\u003eAftermarket replacement; not OEM\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Water pump impeller\u003c\/li\u003e\n\u003cli\u003e1 x Impeller key\u003c\/li\u003e\n\u003cli\u003e1 x Insert cup\u003c\/li\u003e\n\u003cli\u003e1 x Wear plate\u003c\/li\u003e\n\u003cli\u003e1 x Wear-plate-to-housing gasket\u003c\/li\u003e\n\u003cli\u003e1 x Wear-plate-to-base gasket\u003c\/li\u003e\n\u003cli\u003e1 x Water-pump gasket\u003c\/li\u003e\n\u003cli\u003e1 x Water seal\u003c\/li\u003e\n\u003cli\u003e2 x Pump bolts\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eWater-pump housing is not included.\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eDisconnect the battery or ignition system as appropriate and follow the outboard manufacturer’s service precautions.\u003c\/li\u003e\n\u003cli\u003ePlace the outboard in neutral and support it securely before removing the lower unit.\u003c\/li\u003e\n\u003cli\u003eRemove the lower-unit fasteners and carefully separate the gearcase, taking care with the water tube and shift linkage.\u003c\/li\u003e\n\u003cli\u003eRemove the water-pump cover or pump components to expose the impeller.\u003c\/li\u003e\n\u003cli\u003eRemove the old impeller, key, wear plate, gaskets, seals and related fasteners.\u003c\/li\u003e\n\u003cli\u003eClean the pump housing and mating surfaces thoroughly. Remove old gasket material and inspect the existing housing for grooves, cracks, corrosion or excessive wear.\u003c\/li\u003e\n\u003cli\u003eInstall the new gaskets, wear plate and water seal in the correct order for the engine model.\u003c\/li\u003e\n\u003cli\u003eInstall the impeller key on the driveshaft, align the impeller keyway and seat the new impeller. Rotate the driveshaft in the manufacturer-specified direction while fitting the vanes.\u003c\/li\u003e\n\u003cli\u003eInstall the insert cup and pump cover, then tighten the fasteners to the manufacturer’s specified torque.\u003c\/li\u003e\n\u003cli\u003eReinstall the lower unit, ensuring that the driveshaft, water tube and shift linkage are correctly aligned. Test for proper cooling-water flow before normal operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003eUse the service manual for your exact Yamaha model for component order, torque values and shift-linkage adjustment. Professional installation is recommended.\u003c\/p\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I confirm that this kit fits my Yamaha outboard?\u003c\/summary\u003e\n\u003cp\u003eMatch your complete Yamaha model code and serial information to a compatible parts catalog or service manual. The kit is associated with selected 2-stroke 40 HP and 50 HP applications, but horsepower and stroke alone are not sufficient to confirm fitment.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eDoes this kit include the water-pump housing?\u003c\/summary\u003e\n\u003cp\u003eNo. This is the version supplied without the water-pump housing. Inspect your existing housing and replace it separately if it is worn, damaged or out of specification.\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\u003eCommon signs include overheating, reduced cooling-water flow from the tell-tale outlet, weak flow at idle, damaged or missing impeller vanes, or visible cracking and hardening of the old impeller.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow often should the water-pump components be serviced?\u003c\/summary\u003e\n\u003cp\u003eReplacement intervals depend on the engine manufacturer’s maintenance schedule and operating conditions. Inspect the impeller and pump components regularly, especially after storage, operation in saltwater or sandy water, or any overheating event.\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 kit intended to correspond to the listed Yamaha and Sierra references. Yamaha and Sierra are referenced only for identification and compatibility purposes.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat if my engine uses a different pump housing or impeller?\u003c\/summary\u003e\n\u003cp\u003eDo not install the kit based only on appearance or horsepower. Compare the complete engine model, serial range, existing component dimensions and applicable parts diagram before ordering.\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, year and serial information before purchase.\u003c\/li\u003e\n\u003cli\u003eThis kit does not include the water-pump housing.\u003c\/li\u003e\n\u003cli\u003eDo not operate an outboard with insufficient cooling-water flow.\u003c\/li\u003e\n\u003cli\u003eInspect the existing housing and driveshaft keyway before installation.\u003c\/li\u003e\n\u003cli\u003eFollow the manufacturer’s service manual for torque specifications, assembly order and testing procedures.\u003c\/li\u003e\n\u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMarine replacement parts selected for practical service and repair applications.\u003c\/li\u003e\n\u003cli\u003eClear compatibility references to help customers compare parts before ordering.\u003c\/li\u003e\n\u003cli\u003eSupport is available for model and fitment questions when complete engine information is provided.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723973923131,"sku":"SIE-17IY011","price":23.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_Kit_for_Yamaha_40HP-50HP_2-Stroke_6H4-W0078-00-00_-_JLM_MARINE-8289214.jpg?v=1763038930"},{"product_id":"water-pump-impeller-kit-fits-yamaha-40-50hp-2-stroke-outboards-replaces-6h4-w0078-00-00-18-3429","title":"Water Pump Repair Kit with Housing for Yamaha 2-Stroke 40–55 HP Outboards – 6H4 Code","description":"\u003c!-- 🔧 Table Styles (include only once per page) --\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 {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n  table.ss-table th {\n    white-space:nowrap;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\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\u003csection\u003e\n  \u003ch2\u003eProduct Details\u003c\/h2\u003e\n  \u003cp\u003eThis water pump repair kit includes the water pump housing and is designed for selected Yamaha 2-stroke outboards using the 6H4 code. It is intended for servicing the complete water pump assembly and includes the primary components needed for a water pump replacement.\u003c\/p\u003e\n  \u003cp\u003eThe company application data identifies this product for Yamaha 2-stroke 40–55 HP outboards, including 40 HP, 48 HP, 50 HP, and 55 HP applications listed below. Confirm the exact engine model, year, and 6H4 code before ordering.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eWater pump service kit with housing included.\u003c\/li\u003e\n    \u003cli\u003eDesigned for selected Yamaha 2-stroke 6H4-code outboards.\u003c\/li\u003e\n    \u003cli\u003eSuitable for replacing worn or damaged water pump service components.\u003c\/li\u003e\n    \u003cli\u003eReference application: Yamaha OEM number 6H4-W0078-00 with housing.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003ePart Number References\u003c\/h2\u003e\n  \u003cp\u003eThe following numbers are reference listings associated with this water pump application. They are provided for identification and interchange research only; always compare the original assembly and engine details before purchase.\u003c\/p\u003e\n  \u003cdiv class=\"ss-table-wrap\"\u003e\n    \u003ctable class=\"ss-table\" aria-label=\"Part Number References\"\u003e\n      \u003cthead\u003e\n        \u003ctr\u003e\n\u003cth\u003eBrand or Source\u003c\/th\u003e\n\u003cth\u003eReference Number\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\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-00\u003c\/td\u003e\n\u003ctd\u003eCompany reference; housing included\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-00-00\u003c\/td\u003e\n\u003ctd\u003eCatalog reference for the 6H4 water pump repair kit\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-A0-00\u003c\/td\u003e\n\u003ctd\u003eCatalog reference associated with the same application family\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3429\u003c\/td\u003e\n\u003ctd\u003eAftermarket water pump kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n  \u003cp\u003eFitment is limited to Yamaha 2-stroke outboards using the 6H4 code. The horsepower and year ranges below come from the company application data.\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\n        \u003ctr\u003e\n          \u003cth\u003eBrand\u003c\/th\u003e\n          \u003cth\u003eRated HP\u003c\/th\u003e\n          \u003cth\u003eStroke\u003c\/th\u003e\n          \u003cth\u003eYears\u003c\/th\u003e\n          \u003cth\u003eEngine Code\u003c\/th\u003e\n          \u003cth\u003eApplication Notes\u003c\/th\u003e\n        \u003c\/tr\u003e\n      \u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eYamaha\u003c\/td\u003e\n          \u003ctd\u003e40\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1984–1987\u003c\/td\u003e\n          \u003ctd\u003e6H4\u003c\/td\u003e\n          \u003ctd\u003eSelected 40 HP applications\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eYamaha\u003c\/td\u003e\n          \u003ctd\u003e40\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1992–1994\u003c\/td\u003e\n          \u003ctd\u003e6H4\u003c\/td\u003e\n          \u003ctd\u003eSelected 40 HP applications\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eYamaha\u003c\/td\u003e\n          \u003ctd\u003e48\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1995–2000\u003c\/td\u003e\n          \u003ctd\u003e6H4\u003c\/td\u003e\n          \u003ctd\u003eSelected 48 HP applications\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eYamaha\u003c\/td\u003e\n          \u003ctd\u003e50\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1984–1987\u003c\/td\u003e\n          \u003ctd\u003e6H4\u003c\/td\u003e\n          \u003ctd\u003eSelected 50 HP applications\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eYamaha\u003c\/td\u003e\n          \u003ctd\u003e50\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1992–1994\u003c\/td\u003e\n          \u003ctd\u003e6H4\u003c\/td\u003e\n          \u003ctd\u003eSelected 50 HP applications\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eYamaha\u003c\/td\u003e\n          \u003ctd\u003e55\u003c\/td\u003e\n          \u003ctd\u003e2-Stroke\u003c\/td\u003e\n          \u003ctd\u003e1989–1995\u003c\/td\u003e\n          \u003ctd\u003e6H4\u003c\/td\u003e\n          \u003ctd\u003eSelected 55 HP applications\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n  \u003cdl\u003e\n    \u003cdt\u003eProduct Type\u003c\/dt\u003e\n    \u003cdd\u003eWater pump repair kit with housing\u003c\/dd\u003e\n    \u003cdt\u003eApplication\u003c\/dt\u003e\n    \u003cdd\u003eSelected Yamaha 2-stroke outboards with the 6H4 code\u003c\/dd\u003e\n    \u003cdt\u003eHorsepower Range\u003c\/dt\u003e\n    \u003cdd\u003e40–55 HP, including listed 40 HP, 48 HP, 50 HP, and 55 HP applications\u003c\/dd\u003e\n    \u003cdt\u003eHousing\u003c\/dt\u003e\n    \u003cdd\u003eIncluded\u003c\/dd\u003e\n    \u003cdt\u003eInstallation\u003c\/dt\u003e\n    \u003cdd\u003eReplacement water pump service installation; verify the exact engine application before fitting\u003c\/dd\u003e\n  \u003c\/dl\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n  \u003cp\u003eThis product is sold as a water pump service kit with the housing included. The kit is intended to replace the water pump assembly components required for the stated application. Exact component styles and hardware may vary by engine model and production version, so compare the supplied parts with the original assembly before installation.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eWater pump housing\u003c\/li\u003e\n    \u003cli\u003eWater pump impeller\u003c\/li\u003e\n    \u003cli\u003eWater pump service gaskets and wear components\u003c\/li\u003e\n    \u003cli\u003eInstallation hardware and related water pump service parts for the applicable 6H4 assembly\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n  \u003col\u003e\n    \u003cli\u003eConfirm the outboard model, year, horsepower, 6H4 code, and original water pump configuration before beginning work.\u003c\/li\u003e\n    \u003cli\u003eDisconnect the battery and place the outboard in neutral.\u003c\/li\u003e\n    \u003cli\u003eRemove the lower unit according to the manufacturer's service procedure, supporting it securely during removal.\u003c\/li\u003e\n    \u003cli\u003eRemove the existing water pump housing and inspect the driveshaft, keyway, water tube, and mating surfaces.\u003c\/li\u003e\n    \u003cli\u003eClean away old gasket material and debris without damaging the sealing surfaces.\u003c\/li\u003e\n    \u003cli\u003eInstall the new water pump service components and housing in the correct order for the specific engine model.\u003c\/li\u003e\n    \u003cli\u003eInstall the impeller with the vanes oriented in the correct direction for driveshaft rotation.\u003c\/li\u003e\n    \u003cli\u003eReassemble the water pump and lower unit using the manufacturer's specified tightening sequence and torque values.\u003c\/li\u003e\n    \u003cli\u003eReconnect the shift linkage and water tube, then verify that the lower unit is securely mounted.\u003c\/li\u003e\n    \u003cli\u003eRun the engine using the correct water supply procedure and confirm a strong cooling-water tell-tale stream before normal operation.\u003c\/li\u003e\n  \u003c\/ol\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eMaintenance \u0026amp; Troubleshooting\u003c\/h2\u003e\n  \u003cp\u003eInspect the water pump whenever the engine shows overheating symptoms, reduced tell-tale flow, or signs of cooling-system restriction. Replace the impeller and related service components when they are cracked, brittle, deformed, or excessively worn. Maintenance intervals depend on operating hours, storage conditions, and exposure to salt, sand, or silt.\u003c\/p\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow do I confirm that this kit fits my engine?\u003c\/summary\u003e\n    \u003cp\u003eCheck the engine model, year, horsepower, and 6H4 code against the compatibility table. Do not rely on horsepower alone because Yamaha applications can vary by model and production year.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes this product include the water pump housing?\u003c\/summary\u003e\n    \u003cp\u003eYes. The company product record identifies this water pump service kit as a housing-included version.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat are common signs of a failing water pump?\u003c\/summary\u003e\n    \u003cp\u003ePossible signs include overheating, weak or missing tell-tale flow, reduced cooling-water circulation, and visible impeller damage during inspection.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhy might the engine still overheat after installation?\u003c\/summary\u003e\n    \u003cp\u003eCheck impeller orientation, gasket alignment, water-tube engagement, intake passages, the tell-tale outlet, thermostat, and other cooling-system components. If the problem continues, stop operating the engine and have it inspected by a qualified marine technician.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this an OEM Yamaha part?\u003c\/summary\u003e\n    \u003cp\u003eThis listing is for a replacement water pump service kit. Yamaha and aftermarket numbers are shown only as reference numbers; the product should not be represented as a genuine Yamaha-manufactured part.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eVerify the complete engine model and 6H4 application before ordering.\u003c\/li\u003e\n    \u003cli\u003eCompare the original housing, impeller, gaskets, key, and mounting hardware with the supplied parts before installation.\u003c\/li\u003e\n    \u003cli\u003eFollow the manufacturer's service manual for removal, installation, torque values, lubrication, and testing.\u003c\/li\u003e\n    \u003cli\u003eDo not operate an outboard that is overheating or not producing a normal cooling-water tell-tale stream.\u003c\/li\u003e\n    \u003cli\u003eProfessional installation is recommended when the correct application or installation procedure is uncertain.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMarine Replacement Parts\u003c\/strong\u003e — Replacement components for common outboard maintenance and repair applications.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Product information is organized around engine model, horsepower, year, and part-number references.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSupport for Routine Service\u003c\/strong\u003e — Practical parts information to help customers identify the correct maintenance component before ordering.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723973955899,"sku":"22KY026","price":45.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/22KY026_1_3d96c961-5dea-42e1-9da4-4db24678e1fe.jpg?v=1763038932"},{"product_id":"carburetor-rebuild-kit-fits-yamaha-40-50-hp-replaces-6h4-w0093-03-00-6h4-w0093-04-00","title":"Carburetor Repair Seal Kit for Yamaha 25–50 HP and Nissan\/Tohatsu 60–70 HP Outboards","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\u003ecarburetor repair seal kit\u003c\/strong\u003e is designed for selected Yamaha outboard applications from 25 HP through 50 HP, as well as selected Nissan\/Tohatsu 2-stroke 60 HP and 70 HP outboards. It is intended to renew the seals and related service components in the carburetor system during maintenance or repair.\u003c\/p\u003e\n\u003cp\u003eFor Yamaha applications, the kit is associated with OEM references \u003cstrong\u003e6H4-W0093-02\u003c\/strong\u003e, \u003cstrong\u003e6H4-W0093-03\u003c\/strong\u003e, and \u003cstrong\u003e6H4-W0093-04\u003c\/strong\u003e, and with Sierra reference \u003cstrong\u003e18-7768\u003c\/strong\u003e. For Nissan\/Tohatsu applications, the company listing identifies OEM references \u003cstrong\u003e3F3-87122-1\u003c\/strong\u003e, \u003cstrong\u003e3F3-87122-0\u003c\/strong\u003e, and \u003cstrong\u003e3F3871220\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCarburetor repair seal kit for specified marine outboard applications.\u003c\/li\u003e\n  \u003cli\u003eSupports carburetor service by replacing worn or deteriorated sealing components.\u003c\/li\u003e\n  \u003cli\u003eUse the exact engine model, year, and OEM reference to confirm compatibility before ordering.\u003c\/li\u003e\n  \u003cli\u003eAftermarket replacement; not an original equipment manufacturer component.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eThese are the manufacturer and aftermarket references listed for the applicable engine families. A number appearing in the matrix does not by itself confirm fitment for every 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\u003eEngine Brand\u003c\/th\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\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-02\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-03\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-04\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference\u003c\/td\u003e\n\u003ctd\u003e18-7768\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eNissan\/Tohatsu\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003ctd\u003e3F3-87122-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eNissan\/Tohatsu\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003ctd\u003e3F3-87122-0\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eNissan\/Tohatsu\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003ctd\u003e3F3871220\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 the brand, model designation, horsepower, stroke type, and production year of your engine before purchasing.\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\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eYears\u003c\/th\u003e\n\u003cth\u003eApplicable Reference\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e25QEO\u003c\/td\u003e\n\u003ctd\u003e25\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e1993–1994\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-02 \/ 6H4-W0093-03 \/ 6H4-W0093-04\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e40V, 40VM, 40VE\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e1995–2014\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-02 \/ 6H4-W0093-03 \/ 6H4-W0093-04\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eC40T, C40TL\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e1995–2002\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-02 \/ 6H4-W0093-03 \/ 6H4-W0093-04\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e40YET\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e2005–2007\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-02 \/ 6H4-W0093-03 \/ 6H4-W0093-04\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e50H, 50HR, 50HM, 50HW, 50HE\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e1995–2003\u003c\/td\u003e\n\u003ctd\u003e6H4-W0093-02 \/ 6H4-W0093-03 \/ 6H4-W0093-04\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eNissan\/Tohatsu\u003c\/td\u003e\n\u003ctd\u003eM60C, 3-cylinder\u003c\/td\u003e\n\u003ctd\u003e60\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e3F3-87122-1 \/ 3F3-87122-0 \/ 3F3871220\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eNissan\/Tohatsu\u003c\/td\u003e\n\u003ctd\u003eM70C, 3-cylinder\u003c\/td\u003e\n\u003ctd\u003e70\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eNot specified in company record\u003c\/td\u003e\n\u003ctd\u003e3F3-87122-1 \/ 3F3-87122-0 \/ 3F3871220\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\u003eCarburetor repair seal kit\u003c\/dd\u003e\n  \u003cdt\u003eFitment Type\u003c\/dt\u003e\n\u003cdd\u003eSelected Yamaha, Nissan, and Tohatsu marine outboards\u003c\/dd\u003e\n  \u003cdt\u003eYamaha Coverage\u003c\/dt\u003e\n\u003cdd\u003e25QEO, selected 40 HP models, and selected 50 HP models listed above\u003c\/dd\u003e\n  \u003cdt\u003eNissan\/Tohatsu Coverage\u003c\/dt\u003e\n\u003cdd\u003eM60C and M70C 2-stroke, 3-cylinder outboards\u003c\/dd\u003e\n  \u003cdt\u003eYamaha OEM References\u003c\/dt\u003e\n\u003cdd\u003e6H4-W0093-02, 6H4-W0093-03, 6H4-W0093-04\u003c\/dd\u003e\n  \u003cdt\u003eNissan\/Tohatsu OEM References\u003c\/dt\u003e\n\u003cdd\u003e3F3-87122-1, 3F3-87122-0, 3F3871220\u003c\/dd\u003e\n  \u003cdt\u003eAftermarket Reference\u003c\/dt\u003e\n\u003cdd\u003eSierra 18-7768 for listed Yamaha applications\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eReplacement service part; installation should follow the engine service manual\u003c\/dd\u003e\n  \u003cdt\u003eManufacturer Status\u003c\/dt\u003e\n\u003cdd\u003eAftermarket replacement\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cp\u003eThis listing is for one carburetor repair seal kit. The company catalog identifies it as a seal kit but does not provide a complete itemized component list or a confirmed quantity for every individual seal. Match the kit and your original carburetor against the applicable OEM reference before installation.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the battery and shut off the fuel supply before beginning work. Allow the engine to cool completely.\u003c\/li\u003e\n  \u003cli\u003ePlace an absorbent cloth beneath the carburetor area and safely contain any fuel that may drain during disassembly.\u003c\/li\u003e\n  \u003cli\u003ePhotograph or label fuel lines, linkages, and hoses before removing them so they can be returned to their original positions.\u003c\/li\u003e\n  \u003cli\u003eRemove the carburetor or carburetor assembly according to the engine service manual.\u003c\/li\u003e\n  \u003cli\u003eDisassemble the carburetor on a clean work surface and retain reusable hardware in an organized manner.\u003c\/li\u003e\n  \u003cli\u003eClean suitable metal components with a marine-safe carburetor cleaner. Do not use wire or hard tools that could enlarge jets or damage sealing surfaces.\u003c\/li\u003e\n  \u003cli\u003eReplace the applicable old seals and gaskets with the matching components from the kit. Do not force a seal into a groove if its size or profile does not match the original.\u003c\/li\u003e\n  \u003cli\u003eReassemble the carburetor using the service manual’s torque, float-height, adjustment, and synchronization specifications.\u003c\/li\u003e\n  \u003cli\u003eReinstall the carburetor, reconnect all fuel lines and linkages, inspect for leaks, and verify proper operation before returning the engine to service.\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 that this kit fits my engine?\u003c\/summary\u003e\n  \u003cp\u003eCompare your engine brand, exact model designation, horsepower, stroke type, and production year with the compatibility table. Also compare the OEM number stamped or listed for your original carburetor components. Model families can use different carburetor parts even when horsepower is similar.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this a complete carburetor?\u003c\/summary\u003e\n  \u003cp\u003eNo. This is a carburetor repair seal kit. It is supplied for servicing the applicable carburetor system and is not a complete replacement carburetor assembly.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDoes the kit fit both Yamaha and Nissan\/Tohatsu engines?\u003c\/summary\u003e\n  \u003cp\u003eThe company catalog lists separate Yamaha and Nissan\/Tohatsu application groups for this product. Fitment is limited to the specific models and reference numbers shown above; it should not be assumed that every Yamaha, Nissan, or Tohatsu engine is compatible.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eCan I use the kit to correct poor engine performance?\u003c\/summary\u003e\n  \u003cp\u003eWorn seals can contribute to fuel leaks, air leaks, hard starting, rough idle, or inconsistent running. Carburetor symptoms can also result from blocked passages, incorrect adjustment, ignition faults, or fuel-system problems, so diagnose the engine before replacing parts.\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 kit. The OEM numbers are provided only as application and cross-reference information.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify the exact engine model, year, stroke type, and OEM reference before ordering.\u003c\/li\u003e\n  \u003cli\u003eDo not mix parts from unrelated carburetor models or assume that similar-looking seals are interchangeable.\u003c\/li\u003e\n  \u003cli\u003eWork in a well-ventilated area away from flames, sparks, and other ignition sources.\u003c\/li\u003e\n  \u003cli\u003eUse the manufacturer’s service manual for float settings, synchronization, torque values, and final adjustment procedures.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended when carburetor disassembly or adjustment experience is limited.\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 Parts Support\u003c\/strong\u003e — We provide replacement parts for outboard maintenance and repair applications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Product references and model information are provided to help you compare your original part before ordering.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAftermarket Value\u003c\/strong\u003e — Replacement components offer a practical alternative for servicing compatible marine engines.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723974054203,"sku":"23CR149","price":50.05,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/23CR149-1.jpg?v=1763038937"},{"product_id":"water-pump-repair-kit-fits-yamaha-40-60hp-replaces-63d-w0078-01-00-sierra-18-3434","title":"Impeller Repair Kit for Yamaha 40\/50 HP 2-Stroke Outboards – Replaces Yamaha 63D-W0078-01-00, Sierra 18-3434","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\u003eimpeller repair kit\u003c\/strong\u003e is designed for selected Yamaha 40 HP and 50 HP 2-stroke outboards. It replaces Yamaha water-pump reference \u003cstrong\u003e63D-W0078-01-00\u003c\/strong\u003e and corresponds to Sierra part number \u003cstrong\u003e18-3434\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThe kit is intended to renew the key wear components of the water-pump assembly, including the impeller, wear plate, insert cup, gasket, key, seals, O-ring, bolts, washers, and pump-housing cover. It is the version supplied without the complete water-pump housing; confirm the housing condition before installation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHelps restore water-pump circulation and cooling-system performance.\u003c\/li\u003e\n  \u003cli\u003eIncludes the impeller, gaskets, wear plate, insert cup, key, seals, O-ring, fasteners, and cover listed below.\u003c\/li\u003e\n  \u003cli\u003eDesigned as an aftermarket replacement for the specified Yamaha application.\u003c\/li\u003e\n  \u003cli\u003eVerify the exact model designation and production year before ordering.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eThese are the customer-facing manufacturer and aftermarket references associated with this repair-kit 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\u003c\/th\u003e\n\u003cth\u003ePart 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\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e63D-W0078-01-00\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\u003e63D-44311-00-00\u003c\/td\u003e\n\u003ctd\u003eRelated water-pump housing reference; housing is not included in this version\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3434\u003c\/td\u003e\n\u003ctd\u003eAftermarket repair-kit 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 available catalog application data identifies this repair-kit application for the following Yamaha outboards. Model suffixes, year ranges, and cylinder configuration must remain matched when checking fitment.\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 or Series\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eYear or Range\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e40 \/ 50\u003c\/td\u003e\n\u003ctd\u003e40–50\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1995–2003\u003c\/td\u003e\n\u003ctd\u003eCatalog range; confirm the exact model suffix\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eP40\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1998\u003c\/td\u003e\n\u003ctd\u003eSpecific catalog application\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eC40, 3-cylinder\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1997–2002\u003c\/td\u003e\n\u003ctd\u003eConfirm 3-cylinder configuration\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eC50\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1999–2001\u003c\/td\u003e\n\u003ctd\u003eConfirm the exact model suffix\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eF40 2.6L\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e1999\u003c\/td\u003e\n\u003ctd\u003eCatalog-listed application; verify the 2.6L model designation before purchase\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eF50\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e1995–2003\u003c\/td\u003e\n\u003ctd\u003eCatalog-listed application; confirm the exact model and year\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eP50\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1995–1996\u003c\/td\u003e\n\u003ctd\u003eSpecific catalog application\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eF60\u003c\/td\u003e\n\u003ctd\u003e60\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e2002–2003\u003c\/td\u003e\n\u003ctd\u003eCatalog-listed application; verify the exact model suffix\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e The application information above is not a blanket fitment claim for every Yamaha 40–60 HP engine. Yamaha model families can use different water-pump components. Compare the original parts and consult the engine service information when the model, year, cylinder configuration, or displacement differs.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eImpeller repair kit\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eWater-pump cooling-system service\u003c\/dd\u003e\n  \u003cdt\u003eHousing Included\u003c\/dt\u003e\n  \u003cdd\u003eNo complete water-pump housing; a pump-housing cover is included as listed\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n  \u003cdd\u003eReplacement service part; installation should follow the applicable Yamaha service procedure\u003c\/dd\u003e\n  \u003cdt\u003ePrimary OEM Reference\u003c\/dt\u003e\n  \u003cdd\u003eYamaha 63D-W0078-01-00\u003c\/dd\u003e\n  \u003cdt\u003eAftermarket Reference\u003c\/dt\u003e\n  \u003cdd\u003eSierra 18-3434\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 case gasket — Yamaha 63D-44316-00-00\u003c\/li\u003e\n  \u003cli\u003e1 x Impeller — Yamaha 697-44352-00-00\u003c\/li\u003e\n  \u003cli\u003e1 x Wear plate — Yamaha 63D-44323-00-00\u003c\/li\u003e\n  \u003cli\u003e1 x Impeller key — Yamaha 90280-03M03-00\u003c\/li\u003e\n  \u003cli\u003e1 x Insert cup — Yamaha 63D-44322-00-00\u003c\/li\u003e\n  \u003cli\u003e1 x Bolt set of 4 — Yamaha 90119-08M15-00\u003c\/li\u003e\n  \u003cli\u003e1 x Water-pump housing cover — Yamaha 63D-44312-00-00\u003c\/li\u003e\n  \u003cli\u003e4 x Bolt washers — Yamaha 90209-08M02-00\u003c\/li\u003e\n  \u003cli\u003e1 x O-ring — Yamaha 93210-59MG7-00\u003c\/li\u003e\n  \u003cli\u003e1 x Water seal — Yamaha 663-44366-00-00\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eNot included:\u003c\/strong\u003e the complete water-pump housing. Reuse is appropriate only if the existing housing is serviceable and undamaged.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eTurn the engine off, allow it to cool, and follow all applicable marine-service safety procedures.\u003c\/li\u003e\n  \u003cli\u003eRemove the lower unit according to the engine service manual.\u003c\/li\u003e\n  \u003cli\u003eRemove the existing water-pump cover and disassemble the pump in order, recording the position of each component.\u003c\/li\u003e\n  \u003cli\u003eInspect the existing housing, driveshaft keyway, water tube, and mounting surfaces for scoring, corrosion, blockage, or other damage.\u003c\/li\u003e\n  \u003cli\u003eClean the mating surfaces and install the new gasket, wear plate, insert cup, impeller key, and impeller.\u003c\/li\u003e\n  \u003cli\u003eInstall the impeller with the vanes oriented for the direction of shaft rotation specified by the service procedure.\u003c\/li\u003e\n  \u003cli\u003eFit the O-ring, water seal, cover, washers, and fasteners. Tighten fasteners to the manufacturer's specified torque.\u003c\/li\u003e\n  \u003cli\u003eReinstall the lower unit, ensuring that the driveshaft and water tube engage correctly.\u003c\/li\u003e\n  \u003cli\u003eRun the engine using the appropriate water supply and confirm cooling-water flow and normal operating temperature before returning the boat to service.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eMaintenance \u0026amp; Troubleshooting\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat symptoms can indicate a worn water-pump impeller?\u003c\/summary\u003e\n  \u003cp\u003eOverheating, a weak or intermittent tell-tale stream, reduced cooling-water flow, or damaged and missing impeller vanes can indicate that the water pump requires service. A blocked water passage or damaged housing can produce similar symptoms and should also be checked.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDoes this kit include the complete water-pump housing?\u003c\/summary\u003e\n  \u003cp\u003eNo. This repair-kit configuration is supplied without the complete water-pump housing. It includes the water-pump housing cover and the other components listed in the package contents. Inspect the existing housing before installation.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWill this fit every Yamaha 40–60 HP outboard?\u003c\/summary\u003e\n  \u003cp\u003eNo. The application is limited to the Yamaha model, stroke, cylinder, displacement, and year combinations listed above. Do not rely on horsepower alone; compare the original part number and exact engine model designation.\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 listing is for an aftermarket replacement kit. Yamaha part numbers are shown only as OEM reference numbers for identification and fitment checking.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhen should the impeller be replaced?\u003c\/summary\u003e\n  \u003cp\u003eReplace the impeller when inspection shows hardened, cracked, distorted, or missing vanes, or when cooling-water flow is reduced. Follow the maintenance interval and inspection guidance for the specific engine.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify the exact Yamaha model, year, stroke, cylinder configuration, and OEM reference before ordering.\u003c\/li\u003e\n  \u003cli\u003eDo not install a damaged, scored, or corroded water-pump housing with new internal components.\u003c\/li\u003e\n  \u003cli\u003eUse the applicable service manual for removal, installation, fastener torque, and testing procedures.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended if you are not familiar with outboard lower-unit or water-pump service.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement kit, not an OEM Yamaha component.\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 — Parts selected for common outboard maintenance and repair applications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Customer-facing references and fitment details are provided to support part-number verification.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eService-Ready Components\u003c\/strong\u003e — Replace worn water-pump service parts and inspect related components before returning the engine to operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723974152507,"sku":"SIE-17KY009","price":22.78,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/SIE-17KY009_1_71ea747c-f183-46a1-ad2c-3d2607d78be4.jpg?v=1763038945"},{"product_id":"water-pump-impeller-kit-fits-yamaha-40-50-60hp-2-stroke-4-stroke-replaces-63d-w0078-01-00","title":"Yamaha 40–55 HP 2-Stroke Water Pump Repair Kit Without Housing – 6H4 Code (Replaces 6H4-W0078-00-00)","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 \u003cstrong\u003ewater pump repair kit without housing\u003c\/strong\u003e is designed for Yamaha 2-stroke outboard engines using the 6H4 water-pump application. It services selected 40–55 HP models and helps restore the lower-unit cooling system by replacing the impeller and related service components.\u003c\/p\u003e\n  \u003cp\u003eThe kit is intended for Yamaha 2-stroke 40 HP, 48 HP, 50 HP, and 55 HP applications within the model and year ranges listed below. \u003cstrong\u003eThe water pump housing is not included.\u003c\/strong\u003e Confirm the engine model code, year, and required part number before ordering.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eWater pump repair service kit for Yamaha 6H4-code 2-stroke outboards.\u003c\/li\u003e\n    \u003cli\u003eIncludes service components for the impeller, wear surfaces, gaskets, seals, and related hardware.\u003c\/li\u003e\n    \u003cli\u003eWithout housing; reuse the existing housing only if it is serviceable and matches the application.\u003c\/li\u003e\n    \u003cli\u003eAfter installation, verify proper cooling-water flow before operating the engine under load.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n  \u003cp\u003eThe following manufacturer and aftermarket references are associated with this 6H4-code repair-kit application. Number formats and applications can vary by model year, so verify the exact requirement for your engine.\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\u003eApplication Note\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-W0078-00-00\u003c\/td\u003e\n\u003ctd\u003eWater pump repair kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-A0-00\u003c\/td\u003e\n\u003ctd\u003eWater pump repair kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6H4-W0078-01-00\u003c\/td\u003e\n\u003ctd\u003eWater pump repair kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e663-44311-02-00\u003c\/td\u003e\n\u003ctd\u003eWater pump housing reference associated with the application; housing is not included in this kit\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3429\u003c\/td\u003e\n\u003ctd\u003eAftermarket without-housing service-kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3408\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference associated with the 6H4 application\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\u003eCompatibility is limited to Yamaha 2-stroke outboards using the 6H4 code. Match the complete model designation and manufacturing year before installation.\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\u003eEngine Family\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eYears\u003c\/th\u003e\n\u003cth\u003eCode\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e40 HP outboards\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1984–1987; 1992–1994\u003c\/td\u003e\n\u003ctd\u003e6H4\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e48 HP outboards\u003c\/td\u003e\n\u003ctd\u003e48\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1995–2000\u003c\/td\u003e\n\u003ctd\u003e6H4\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e50 HP outboards\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1984–1987; 1992–1994\u003c\/td\u003e\n\u003ctd\u003e6H4\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e55 HP outboards\u003c\/td\u003e\n\u003ctd\u003e55\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1989–1995\u003c\/td\u003e\n\u003ctd\u003e6H4\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 repair service kit\u003c\/dd\u003e\n    \u003cdt\u003eHousing\u003c\/dt\u003e\n    \u003cdd\u003eNot included\u003c\/dd\u003e\n    \u003cdt\u003eEngine Type\u003c\/dt\u003e\n    \u003cdd\u003eYamaha 2-stroke outboard\u003c\/dd\u003e\n    \u003cdt\u003eApplication Code\u003c\/dt\u003e\n    \u003cdd\u003e6H4\u003c\/dd\u003e\n    \u003cdt\u003eRated Power Range\u003c\/dt\u003e\n    \u003cdd\u003e40–55 HP, subject to the model and year conditions listed above\u003c\/dd\u003e\n    \u003cdt\u003eInstallation\u003c\/dt\u003e\n    \u003cdd\u003eReplacement service installation; inspect the existing housing before reuse\u003c\/dd\u003e\n  \u003c\/dl\u003e\n\n  \u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n  \u003cp\u003eThis is a repair kit supplied \u003cstrong\u003ewithout the water pump housing\u003c\/strong\u003e. The service contents are intended to include the following component types:\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eWater pump impeller\u003c\/li\u003e\n    \u003cli\u003eImpeller key\u003c\/li\u003e\n    \u003cli\u003eInsert cup\u003c\/li\u003e\n    \u003cli\u003eWear plate\u003c\/li\u003e\n    \u003cli\u003eWater pump gaskets, including wear-plate sealing gaskets\u003c\/li\u003e\n    \u003cli\u003eWater seal\u003c\/li\u003e\n    \u003cli\u003eRelated pump bolts and service hardware\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \u003cp\u003e\u003cstrong\u003eNot included:\u003c\/strong\u003e water pump housing. Do not assume that a housing, lower-unit assembly, gearcase oil, or engine-specific fasteners are included unless shown in the package received.\u003c\/p\u003e\n\n  \u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n  \u003col\u003e\n    \u003cli\u003eConfirm the engine model, year, 6H4 code, and required water-pump part number before disassembly.\u003c\/li\u003e\n    \u003cli\u003eDisconnect the battery and follow the engine manufacturer's safety procedures.\u003c\/li\u003e\n    \u003cli\u003eRemove the lower unit according to the service-manual procedure for your specific Yamaha model.\u003c\/li\u003e\n    \u003cli\u003eRemove the existing water-pump components and note the orientation of the impeller, key, plates, gaskets, and seals.\u003c\/li\u003e\n    \u003cli\u003eInspect the existing housing carefully. Replace it separately if it is worn, scored, distorted, corroded, or otherwise unserviceable; this kit does not include a housing.\u003c\/li\u003e\n    \u003cli\u003eClean the mating surfaces and remove old gasket material without damaging the sealing surfaces.\u003c\/li\u003e\n    \u003cli\u003eInstall the new impeller, key, insert cup, wear plate, gaskets, seal, and hardware in the correct order for the engine model.\u003c\/li\u003e\n    \u003cli\u003eApply only the lubricant and sealant specified by the applicable service manual, and tighten fasteners to the manufacturer's specifications.\u003c\/li\u003e\n    \u003cli\u003eReinstall the lower unit, refill gearcase lubricant if required by the service procedure, and reconnect the battery.\u003c\/li\u003e\n    \u003cli\u003eStart the engine using the correct water-supply procedure and verify a strong tell-tale stream and normal cooling operation before use.\u003c\/li\u003e\n  \u003c\/ol\u003e\n\n  \u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n  \u003cdetails\u003e\u003csummary\u003eDoes this kit include the water pump housing?\u003c\/summary\u003e\u003cp\u003eNo. The company product record identifies this as a 2-stroke water pump service kit supplied without housing. Inspect your existing housing and replace it separately if necessary.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhich Yamaha engines does this kit fit?\u003c\/summary\u003e\u003cp\u003eThe listed application is Yamaha 2-stroke 6H4-code outboards in the 40–55 HP range: 40 HP models from 1984–1987 and 1992–1994, 48 HP models from 1995–2000, 50 HP models from 1984–1987 and 1992–1994, and 55 HP models from 1989–1995. Verify the complete model code and part-number requirement before ordering.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWill this fit a Yamaha F40, F50, or F60 four-stroke?\u003c\/summary\u003e\u003cp\u003eNo compatibility claim is made for those four-stroke models. The exact product record specifies Yamaha 2-stroke 6H4-code applications only.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhat are the symptoms of a worn water-pump impeller?\u003c\/summary\u003e\u003cp\u003eCommon symptoms include a weak or absent tell-tale stream, overheating warnings, elevated operating temperature, or damaged, brittle, cracked, or missing impeller vanes. Stop operation if the engine overheats and diagnose the cooling system before continued use.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eHow often should the impeller be serviced?\u003c\/summary\u003e\u003cp\u003eInspect and service the water pump according to the engine manufacturer's maintenance schedule and operating conditions. Saltwater, sand, silt, and extended storage can accelerate wear.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eIs this an OEM Yamaha part?\u003c\/summary\u003e\u003cp\u003eThis listing is for a replacement service kit. It is not represented as a genuine Yamaha-branded OEM part.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhat should I check before ordering?\u003c\/summary\u003e\u003cp\u003eMatch the engine brand, complete model designation, manufacturing year, 6H4 application code, stroke type, and required water-pump reference. Also confirm that you need a kit without housing.\u003c\/p\u003e\u003c\/details\u003e\n  \u003cdetails\u003e\u003csummary\u003eWhat are your shipping speeds and costs?\u003c\/summary\u003e\u003cp\u003eStandard shipping is available to most regions. Delivery times and any expedited options are calculated and displayed at checkout based on the destination.\u003c\/p\u003e\u003c\/details\u003e\n\n  \u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eVerify the complete engine model, year, 6H4 code, and part-number requirement before purchase.\u003c\/li\u003e\n    \u003cli\u003eThis kit is for Yamaha 2-stroke applications listed above; do not transfer the fitment to four-stroke models.\u003c\/li\u003e\n    \u003cli\u003eThe water pump housing is not included. Inspect the existing housing before reusing it.\u003c\/li\u003e\n    \u003cli\u003eUse the correct service manual and torque specifications for the specific engine.\u003c\/li\u003e\n    \u003cli\u003eProfessional installation is recommended if you are not experienced with lower-unit or water-pump 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 — Service components selected for common outboard maintenance and repair applications.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Fitment information is organized by engine family, stroke, horsepower, code, and year where available.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSupport Before Installation\u003c\/strong\u003e — Verify your model and required reference before ordering or beginning service.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723974185275,"sku":"17KY011","price":30.58,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/17KY0111_6c1a8f88-f792-44e1-9e06-93c9d33949c1.jpg?v=1763038947"},{"product_id":"water-pump-impeller-repair-kit-fits-yamaha-40-60-hp-replaces-6h3-w0078-02-00","title":"Water Pump Repair Kit Without Housing – Yamaha 2-Stroke 60-70 HP and 4-Stroke F50\/T50\/T60 – OEM 6H3-W0078-02","description":"\u003csection\u003e\n\u003c!-- 🔧 Table Styles (include only once per page) --\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 {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n  table.ss-table th {\n    white-space:nowrap;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eWater Pump Repair Kit Without Housing\u003c\/strong\u003e is designed to service the cooling system on selected Yamaha outboard motors. The kit replaces the water pump service components associated with Yamaha OEM part number \u003cstrong\u003e6H3-W0078-02\u003c\/strong\u003e and is supplied without the water pump housing.\u003c\/p\u003e\n\u003cp\u003eIt is intended for selected Yamaha 2-stroke 60-70 HP models and selected 4-stroke F50, T50, and T60 models. Because Yamaha fitment varies by model and year, confirm your complete engine model and the original water pump part number before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eWater pump service kit supplied without the pump housing.\u003c\/li\u003e\n  \u003cli\u003eIncludes an impeller, gaskets, plates, insert, O-ring, key, and installation hardware as listed below.\u003c\/li\u003e\n  \u003cli\u003eHelps restore water-pump performance during routine cooling-system service.\u003c\/li\u003e\n  \u003cli\u003eAftermarket replacement for the listed Yamaha OEM reference.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Reference\u003c\/h2\u003e\n\u003cp\u003eUse the following reference to compare this service kit with the part required for your engine.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Reference\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eReference\u003c\/th\u003e\n        \u003cth\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e6H3-W0078-02\u003c\/td\u003e\n        \u003ctd\u003eWater pump repair kit 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 identify the following Yamaha applications. Model, horsepower, stroke, and year conditions should be considered together.\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\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel or Model Family\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eYears\u003c\/th\u003e\n        \u003cth\u003eFitment Notes\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e60, C60, P60, 70, C70\u003c\/td\u003e\n        \u003ctd\u003e60-70\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1997-2003\u003c\/td\u003e\n        \u003ctd\u003eConfirm the exact model designation before installation.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eC60, E60, P60, 70\u003c\/td\u003e\n        \u003ctd\u003e60-70\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1992-1996\u003c\/td\u003e\n        \u003ctd\u003eConfirm the exact model designation before installation.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF50, T50\u003c\/td\u003e\n        \u003ctd\u003e50\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1996\u003c\/td\u003e\n        \u003ctd\u003eVerify the original water pump reference.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eT50, T60\u003c\/td\u003e\n        \u003ctd\u003e50-60\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1997-2023\u003c\/td\u003e\n        \u003ctd\u003eVerify the exact model and year before ordering.\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 repair service kit\u003c\/dd\u003e\n  \u003cdt\u003eHousing\u003c\/dt\u003e\n  \u003cdd\u003eNot included; supplied without the water pump housing\u003c\/dd\u003e\n  \u003cdt\u003ePrimary OEM Reference\u003c\/dt\u003e\n  \u003cdd\u003e6H3-W0078-02\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n  \u003cdd\u003eReplacement service part; installation requires removal and servicing of the water pump assembly\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eSelected Yamaha 2-stroke 60-70 HP and 4-stroke F50\/T50\/T60 outboards listed in the compatibility table\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 Cartridge Insert (663-44322-00-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Impeller (6H3-44352-00-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Water Pump Gasket 1 (6H3-44315-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Cartridge Outer Plate (6H3-44323-00-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Cartridge Gasket (6H3-44324-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Water Pump Gasket 2 (688-44316-A0-00)\u003c\/li\u003e\n  \u003cli\u003e1 x O-Ring (93210-46044-00)\u003c\/li\u003e\n  \u003cli\u003e2 x Bolts with Washer (90119-08M14-00)\u003c\/li\u003e\n  \u003cli\u003e2 x Bolts with Washer (90119-08M33-00)\u003c\/li\u003e\n  \u003cli\u003e1 x Woodruff Key (90280-03M03-00)\u003c\/li\u003e\n  \u003cli\u003e\u003cstrong\u003eWater pump housing is not included.\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the battery and make sure the engine is secure before beginning work.\u003c\/li\u003e\n  \u003cli\u003eShift the outboard into neutral and remove the lower-unit mounting hardware according to the engine service procedure.\u003c\/li\u003e\n  \u003cli\u003eCarefully separate the lower unit from the driveshaft housing.\u003c\/li\u003e\n  \u003cli\u003eRemove the water pump cover and expose the existing impeller and service components.\u003c\/li\u003e\n  \u003cli\u003eRemove the old impeller, gaskets, plates, insert, O-ring, and key as applicable. Note the orientation of each part during disassembly.\u003c\/li\u003e\n  \u003cli\u003eClean all mating surfaces thoroughly and remove old gasket material, corrosion, and debris.\u003c\/li\u003e\n  \u003cli\u003eInstall the replacement plates, gaskets, insert, O-ring, and other kit components in the correct order for your engine.\u003c\/li\u003e\n  \u003cli\u003eFit the new impeller onto the driveshaft and align it with the Woodruff key. Follow the engine manufacturer’s specified vane direction.\u003c\/li\u003e\n  \u003cli\u003eReinstall the water pump cover and tighten the fasteners to the manufacturer’s specified torque.\u003c\/li\u003e\n  \u003cli\u003eReattach the lower unit, reconnect the battery, and test the engine in water. Confirm a strong cooling-water tell-tale stream before normal operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e This is a service kit without a pump housing. Reuse your existing housing only if it is suitable for continued service; replace it separately if it is worn, damaged, or out of specification.\u003c\/p\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I confirm that this kit fits my Yamaha outboard?\u003c\/summary\u003e\u003cp\u003eCompare your complete Yamaha model designation, horsepower, stroke type, and year with the compatibility table. Also verify that your original water pump service part corresponds to OEM reference 6H3-W0078-02. A horsepower match alone is not sufficient.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes this kit include the water pump housing?\u003c\/summary\u003e\u003cp\u003eNo. This product is a water pump repair kit supplied without the water pump housing. The existing housing must be reused only if it remains serviceable, or replaced separately when necessary.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat are the signs of a failing water pump impeller?\u003c\/summary\u003e\u003cp\u003eCommon signs include overheating, a weak or intermittent tell-tale stream, reduced cooling-water flow, or a visibly cracked, brittle, deformed, or damaged impeller.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow often should an outboard water pump impeller be replaced?\u003c\/summary\u003e\u003cp\u003eReplacement intervals depend on the engine manufacturer’s maintenance schedule and operating conditions. Inspect the impeller regularly and consider more frequent service in saltwater, sandy, silty, or debris-filled environments.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhy might the engine still overheat after installation?\u003c\/summary\u003e\u003cp\u003eCheck for blocked intake screens or cooling passages, a damaged or unsuitable pump housing, incorrect gasket placement, a damaged key, thermostat problems, or improper installation. If the problem continues, stop operating the engine and consult the service manual or a qualified marine technician.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this an OEM Yamaha part?\u003c\/summary\u003e\u003cp\u003eNo. This is an aftermarket replacement service kit identified for comparison with Yamaha OEM reference 6H3-W0078-02. Yamaha is a trademark of its respective owner and is used only to describe compatibility.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat should I check before ordering?\u003c\/summary\u003e\u003cp\u003eCheck the exact engine model, year, horsepower, stroke type, and original pump reference. Confirm that the kit’s no-housing configuration matches your repair plan.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eDisconnect the battery and follow the engine manufacturer’s service procedures before beginning work.\u003c\/li\u003e\n  \u003cli\u003eNever operate an outboard with inadequate cooling-water flow.\u003c\/li\u003e\n  \u003cli\u003eVerify the engine model, year, stroke type, and OEM reference before purchase.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended if you are not experienced with lower-unit or water-pump service.\u003c\/li\u003e\n  \u003cli\u003eThis listing is for a repair kit without the water pump housing; the housing is not included.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement, not an OEM Yamaha component.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eMarine replacement parts selected for practical maintenance and repair applications.\u003c\/li\u003e\n  \u003cli\u003eClear compatibility information to help match the part to the correct engine application.\u003c\/li\u003e\n  \u003cli\u003eManufacturer-direct value for routine outboard service needs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723974218043,"sku":"20KY003","price":34.32,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Water_Pump_Impeller_Kit_for_Yamaha_40_-_50_HP_6H3-W0078_-_JLM_MARINE-8288751.jpg?v=1763038949"}],"url":"https:\/\/seasierra.com\/collections\/yamaha-40-50hp-2-stroke-outboard-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}