{"title":"Yamaha 75-250HP 2-Stroke Outboard Engine","description":"\u003csection id=\"hero\" style=\"max-width: 1100px; margin: 0 auto; padding: 16px;\"\u003e\n  \u003cp\u003eThis page supports Yamaha 75–250HP 2‑Stroke outboard engines. Use it to find compatible parts and service guidance, including maintenance intervals, common replacement items, and troubleshooting tips. You can also browse our main Yamaha outboard parts 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  \u003cp\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\" style=\"display:inline-block;padding:10px 16px;border:1px solid #0b5;border-radius:6px;text-decoration:none;color:#0b5;\"\u003eBrowse All Yamaha Parts\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"max-width: 1100px; margin: 0 auto; padding: 16px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 75–250HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eNameplate location: Find the model\/serial plate on the transom bracket (typically port side) or on the swivel bracket. Record the full model code and serial number.\u003c\/li\u003e\n    \u003cli\u003eModel code basics: Examples include 90TLR, 115TXR, 150TXR, 200TXR, 225TXR, 250TXR and HPDI variants (e.g., Z200TXR). Letters often indicate control type and shaft length (S\/L\/X), and a suffix letter can denote the year. Always match parts to the exact code.\u003c\/li\u003e\n    \u003cli\u003ePlatform clues: 75–115HP models are usually inline 2‑strokes, while 150–250HP are V6 2‑strokes. V6 engines have a wider powerhead and larger gearcase. Many engines use oil injection (no fuel premix), with a remote or under‑cowl oil tank.\u003c\/li\u003e\n    \u003cli\u003eGearcase notes: Some V6 models use heavy‑duty gearcases. Prop hub size and seal kits can differ—verify gearcase style before ordering propellers or lower unit seal kits.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"platforms\" style=\"max-width: 1100px; margin: 0 auto; padding: 16px;\"\u003e\n  \u003ch2\u003eEngine Platform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003e75–115HP Inline Series\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; 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 #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eInline 2‑stroke (commonly inline‑3 for 75\/90 and inline‑4 for 115), carbureted or EFI depending on year; typically oil‑injected.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e75TLR, 90TLR, 115TXR (examples; verify by model plate).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eLight weight, strong hole‑shot, straightforward rigging and maintenance.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eIgnition and cooling parts often overlap across nearby horsepower ratings; carb jetting, reeds, and props are model‑specific. Match parts to the exact code and serial.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003e150–250HP V6 Series\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; 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 #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eV6 2‑stroke, carbureted and OX66 EFI options; later years include HPDI direct injection.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e150TXR, 175TXR, 200TXR, 225TXR, 250TXR; HPDI variants such as Z200\/Z225\/Z250 (examples).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eHigh torque for heavier boats, broad propeller selection, proven durability.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eHPDI uses specific high\/medium‑pressure fuel filters; OX66 uses VST filters. Water pump kits and anodes are often shared across years—confirm by model and gearcase type.\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; padding: 16px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are typical guidelines for Yamaha 2‑Stroke outboards; always follow the official service manual for your exact model and operating conditions.\u003c\/p\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; 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 #eee;\"\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eReplace drain\/fill gaskets; inspect for water (milky oil) and metal debris.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\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 #eee;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e100 hours or annually (inspect at 50)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eUse the correct heat range; gap and indexing per manual.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plugs\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eFuel filter \/ water separator\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eReplace inline filter; consider a 10‑micron external separator for ethanol fuel.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e200 hours or every 2 years (inspect yearly)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eReplace full kit if cup\/plate show wear or after sand\/silt use.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-water-pump-repair-kits\"\u003eYamaha Water Pump Repair Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eAnodes (internal\/external)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eInspect 50–100 hours; replace at ~50% depletion\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eDo not paint contact surfaces; match alloy to water type.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-anodes\"\u003eYamaha Anodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eOil injection system check\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eAnnually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eInspect tank strainer, lines, and check valves; verify pump prime and alarm operation.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/hoses\"\u003eHoses \u0026amp; Lines\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eThermostats \u0026amp; poppet valve\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eInspect annually; replace 2–3 years\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eStuck components cause overheat or cool running; replace gaskets on reassembly.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\"\u003eYamaha Outboard Parts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003ePropeller \u0026amp; hardware\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eSeasonally or after impacts\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eInspect blades, hub, thrust washer, tab washer\/cotter, and nut; confirm pitch\/diameter.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-propellers\"\u003eYamaha Propellers\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"max-width: 1100px; margin: 0 auto; padding: 16px;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service Kits – \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-pumps\"\u003eFuel Pumps\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eIgnition \/ Electrical – \u003ca href=\"https:\/\/seasierra.com\/collections\/electrical-items\"\u003eElectrical Items\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropellers \u0026amp; Hardware – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-propellers\"\u003eYamaha Propellers\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase \u0026amp; Seals – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-lower-unit-seal-kits\"\u003eYamaha Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection – \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-anodes\"\u003eYamaha Anodes\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"max-width: 1100px; margin: 0 auto; padding: 16px;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; padding:8px;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ccc; 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 #eee;\"\u003eWeak tell‑tale or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eInspect intake screens for blockage, verify thermostat and poppet operation, and check water pump impeller condition.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eWater pump kit, thermostat, poppet valve, intake screen, anodes\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003ePoor acceleration or power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eCheck prop for damage\/over‑pitch, assess spark plug condition, inspect carburetors or fuel injectors\/VST, and verify fuel filters and lines.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003ePropeller, spark plugs, fuel filter, fuel pump, carburetor kit or injector service\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eDrain stale fuel, confirm choke\/prime enrichment function, check for air leaks at fuel fittings\/primer bulb, and perform a compression test.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eFuel filter, hoses\/primer bulb, carburetor rebuild kit, spark plugs\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eExcessive smoke (2‑Stroke)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eVerify correct oil ratio if premix, inspect oil injection lines and check valves, and avoid extended cold idling.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eOil injection lines\/check valves, spark plugs\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eCheck gear oil level\/condition, inspect for fishing line on prop shaft (seal damage), and evaluate for impact damage.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #eee;\"\u003eLower unit seal kit, bearings, gear set, thrust washer\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; padding: 16px;\"\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\u003eSome service items (anodes, water pump kits, certain ignition components) overlap between years. However, carburetor jets, HPDI\/EFI fuel filters, gearcase seals, and prop hubs are often model‑specific. Always verify by full model code 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 the impeller every 2 years or ~200 hours, sooner after sand\/silt use, low‑flow symptoms, or any overheat event. Full water pump kits are recommended if the cup\/plate show wear.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should gear oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eEvery 100 hours or annually, and immediately after any suspected impact or submersion. Replace crush washers and inspect oil for water or metal.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do you need to confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003ePlease provide the full model code (e.g., 200TXR or Z200TXR), serial number, shaft length, control type (tiller\/remote), and any known year range or fuel system type (carb, EFI\/OX66, HPDI).\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"max-width: 1100px; margin: 0 auto; padding: 16px;\"\u003e\n  \u003cp\u003eReady to find parts by horsepower, year, and model? Browse the main Yamaha outboard collection for a focused selection compatible with your 75–250HP 2‑Stroke.\u003c\/p\u003e\n  \u003cp\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha-outboard-parts\" style=\"display:inline-block;padding:10px 16px;border:1px solid #0b5;border-radius:6px;text-decoration:none;color:#0b5;\"\u003eShop Yamaha Outboard Parts\u003c\/a\u003e\u003c\/p\u003e\n  \u003cp style=\"font-size: 0.95em; color: #555;\"\u003eIf you’re unsure about your model, send us a photo of the nameplate and the part you need and we’ll help verify compatibility.\u003c\/p\u003e\n\u003c\/section\u003e","products":[{"product_id":"thermostat-fits-yamaha-2-stroke-outboard-75-250-hp-replaces-6e5-12411-30-00-688-12411-series","title":"Yamaha 2-Stroke Outboard Thermostat Kit, 115–250 HP – Replaces 6E5-12411-30-00","description":"\u003csection\u003e\n  \u003ch2\u003eProduct Details\u003c\/h2\u003e\n  \u003cp\u003eThis aftermarket \u003cstrong\u003ethermostat kit\u003c\/strong\u003e is designed for selected Yamaha 2-stroke outboard engines from approximately 1991 through 2002, covering compatible 115–250 HP applications. It helps regulate engine operating temperature and supports reliable cooling-system performance when the original thermostat is worn, stuck, or no longer responding correctly.\u003c\/p\u003e\n  \u003cp\u003eThe thermostat is listed as a replacement for Yamaha part number \u003cstrong\u003e6E5-12411-30-00\u003c\/strong\u003e and is cross-referenced with Sierra \u003cstrong\u003e18-3540\u003c\/strong\u003e. Always compare the part number and engine model details before ordering.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eAftermarket thermostat replacement for selected Yamaha 2-stroke outboards.\u003c\/li\u003e\n    \u003cli\u003eDesigned for direct replacement when the listed part number and application match.\u003c\/li\u003e\n    \u003cli\u003eKit includes one thermostat and one thermostat housing gasket.\u003c\/li\u003e\n    \u003cli\u003eThermostat opening rating: approximately 50°C \/ 122°F.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n  \u003cp\u003eUse the following references to compare your original part. Part-number matching should be confirmed together with the engine model, horsepower, stroke, year, and serial-number requirements.\u003c\/p\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  \u003cdiv class=\"ss-table-wrap\"\u003e\n    \u003ctable class=\"ss-table\" aria-label=\"Part Number Interchange\"\u003e\n      \u003cthead\u003e\n        \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003cth\u003eReference\u003c\/th\u003e\n\u003c\/tr\u003e\n      \u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003ctd\u003eReplacement\/OEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-20-00\u003c\/td\u003e\n\u003ctd\u003eAdditional catalog reference; verify application\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-10-00\u003c\/td\u003e\n\u003ctd\u003eAdditional catalog reference; verify application\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e688-12411-10-00\u003c\/td\u003e\n\u003ctd\u003eAdditional catalog reference; verify application\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e688-12411-11-00\u003c\/td\u003e\n\u003ctd\u003eAdditional catalog reference; verify application\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3540\u003c\/td\u003e\n\u003ctd\u003eAftermarket thermostat 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\u003eThe catalog application data for this thermostat identifies selected Yamaha 2-stroke engines in the ranges below. The year ranges are not universal for every variant, so confirm the complete model designation and the required OEM number 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\n        \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eEngine family or model\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eCatalog year range\u003c\/th\u003e\n\u003cth\u003eReference\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\u003e115, C115, P115, S115\u003c\/td\u003e\n\u003ctd\u003e115\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1991–2002, depending on variant\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e130, L130, S130\u003c\/td\u003e\n\u003ctd\u003e130\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1991–2002, depending on variant\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e150, C150, L150, P150, S150, V150, Z150\u003c\/td\u003e\n\u003ctd\u003e150\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1991–2002, depending on variant\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e175, P175, V175, Z175\u003c\/td\u003e\n\u003ctd\u003e175\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1991–2002, depending on variant\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e200, L200, P200, S200, V200, Z200\u003c\/td\u003e\n\u003ctd\u003e200\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1991–2002, depending on variant\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003e225, V225\u003c\/td\u003e\n\u003ctd\u003e225\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1991–1999, depending on variant\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eLX225, LX250, SX225, SX250\u003c\/td\u003e\n\u003ctd\u003e225–250\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eSelected 2003 catalog applications\u003c\/td\u003e\n\u003ctd\u003e6E5-12411-30-00\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 Specs\u003c\/h2\u003e\n  \u003cdl\u003e\n    \u003cdt\u003eProduct Type\u003c\/dt\u003e\n    \u003cdd\u003eOutboard engine thermostat kit\u003c\/dd\u003e\n    \u003cdt\u003eApplication\u003c\/dt\u003e\n    \u003cdd\u003eSelected Yamaha 2-stroke outboard engines\u003c\/dd\u003e\n    \u003cdt\u003eHorsepower Range\u003c\/dt\u003e\n    \u003cdd\u003e115–250 HP, depending on the exact model and year\u003c\/dd\u003e\n    \u003cdt\u003eInstallation\u003c\/dt\u003e\n    \u003cdd\u003eDirect replacement when application and part number match\u003c\/dd\u003e\n    \u003cdt\u003eOpening Temperature\u003c\/dt\u003e\n    \u003cdd\u003eApproximately 50°C \/ 122°F\u003c\/dd\u003e\n    \u003cdt\u003eIncluded Gasket\u003c\/dt\u003e\n    \u003cdd\u003eThermostat housing gasket\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  \u003cul\u003e\n    \u003cli\u003e1 × Thermostat, replacing the listed 6E5-12411-30-00 application\u003c\/li\u003e\n    \u003cli\u003e1 × Thermostat housing gasket, cross-referenced with Yamaha 688-12414-A1-00\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \u003cp\u003e\u003cstrong\u003eNo separate thermostat seal is listed as an included component.\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n  \u003col\u003e\n    \u003cli\u003eDisconnect the battery according to the engine manufacturer's safety procedure.\u003c\/li\u003e\n    \u003cli\u003eAllow the engine to cool completely before opening the cooling system.\u003c\/li\u003e\n    \u003cli\u003ePlace a drain pan below the thermostat housing and remove the housing cover.\u003c\/li\u003e\n    \u003cli\u003eNote the orientation of the original thermostat before removal.\u003c\/li\u003e\n    \u003cli\u003eClean the housing and cover mating surfaces, removing old gasket material without damaging the surfaces.\u003c\/li\u003e\n    \u003cli\u003eInstall the replacement thermostat in the original orientation, followed by the new housing gasket.\u003c\/li\u003e\n    \u003cli\u003eReinstall the cover and tighten the fasteners to the manufacturer's specified torque.\u003c\/li\u003e\n    \u003cli\u003eRestore the cooling system as required, run the engine, and check for leaks and normal temperature operation.\u003c\/li\u003e\n  \u003c\/ol\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n  \u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow do I know if my thermostat is failing?\u003c\/summary\u003e\n    \u003cp\u003ePossible symptoms include overheating, an engine that runs too cool, unstable operating temperature, restricted cooling-water flow, or visible corrosion and deposits around the thermostat. Diagnose the complete cooling system before replacing the part.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this the correct temperature rating for my engine?\u003c\/summary\u003e\n    \u003cp\u003eThis thermostat is listed with an opening temperature of approximately 50°C \/ 122°F. Verify that this temperature and the replacement part number match your engine service information before installation.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eMy exact model is not listed. Will it still fit?\u003c\/summary\u003e\n    \u003cp\u003eDo not assume fitment from horsepower alone. Compare the complete engine model, year, serial range, original thermostat, and required OEM part number with the information above.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this an OEM thermostat?\u003c\/summary\u003e\n    \u003cp\u003eNo. This is an aftermarket replacement kit intended to match the listed application and reference numbers. Yamaha and other brand names and part numbers are used only to identify compatibility.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes the kit include a seal?\u003c\/summary\u003e\n    \u003cp\u003eThe documented package contents include one thermostat and one thermostat housing gasket. A separate thermostat seal is not listed as included.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should the thermostat be replaced?\u003c\/summary\u003e\n    \u003cp\u003eInspect the thermostat during cooling-system service and replace it if it sticks, fails a temperature test, shows corrosion, or does not meet the engine manufacturer's specifications. Follow the maintenance schedule for your specific engine.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eShipping speed and cost\u003c\/summary\u003e\n    \u003cp\u003eShipping options, delivery estimates, and cost are shown at checkout based on the destination and service selected.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWarranty and returns\u003c\/summary\u003e\n    \u003cp\u003eWarranty and return eligibility are governed by the current store policies. Contact support with your order details if you need assistance.\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\u003eConfirm the exact part number and application before ordering.\u003c\/li\u003e\n    \u003cli\u003eNever open the thermostat housing while the engine or coolant is hot.\u003c\/li\u003e\n    \u003cli\u003eUse the manufacturer's torque, gasket, cooling-system, and installation procedures.\u003c\/li\u003e\n    \u003cli\u003eProfessional installation is recommended if you are not familiar with outboard cooling-system service.\u003c\/li\u003e\n    \u003cli\u003eThis is an aftermarket replacement, not an OEM component.\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 — Practical aftermarket parts for routine service and repair.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Product references and compatibility information are provided to help you verify fitment.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCustomer Support\u003c\/strong\u003e — Contact support with your engine details and original part information when you need help confirming an application.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723983196475,"sku":"23TH617","price":21.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Thermostat_Kit_for_Yamaha_2-Stroke_Outboards_-_JLM_MARINE-8291449.jpg?v=1763039359"}],"url":"https:\/\/seasierra.com\/collections\/yamaha-75-250hp-2-stroke-outboard-engine.oembed","provider":"SeaSierra","version":"1.0","type":"link"}