{"title":"Honda 4-Stroke 5-100HP Outboard Engine Parts","description":"\u003csection id=\"hero\" style=\"max-width: 980px; margin: 0 auto; padding: 16px 12px;\"\u003e\n  \u003cp\u003eThis page is tailored for Honda 4-Stroke 5–100HP outboard engines. It helps you find compatible parts and practical service information, including maintenance tips, common replacement categories, and troubleshooting guidance. You can also browse our main Honda collection at any time. Scroll down to the bottom of this page to start browsing parts for this engine, and remember: on the collection page you can 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\/honda-outboard-parts\" style=\"display:inline-block;background:#0a6efd;color:#fff;padding:10px 14px;border-radius:6px;text-decoration:none;\"\u003eBrowse All Honda Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"max-width: 980px; margin: 0 auto; padding: 12px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 5–100HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the nameplate\/serial tag on the transom bracket (port side) or swivel bracket. Record the full model (e.g., BF40D) and serial number.\u003c\/li\u003e\n    \u003cli\u003eModel code basics: “BF” denotes 4‑stroke outboards; the number is horsepower. Suffix letters\/numbers indicate generation and features (e.g., D = later revision; S\/L\/X = shaft length; T = power trim; R = remote control).\u003c\/li\u003e\n    \u003cli\u003ePortable vs mid\/upper midrange: BF5\/8\/9.9\/15\/20 are single\/twin‑cylinder portables; BF25\/30\/40\/50\/60 are typically inline‑3; BF75\/90\/100 are inline‑4. Notes like PGM‑FI indicate EFI vs earlier carbureted versions.\u003c\/li\u003e\n    \u003cli\u003eWhen ordering parts, match by model and serial number range; small changes between generations can affect cooling, fuel, and ignition components.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"max-width: 980px; margin: 0 auto; padding: 12px;\"\u003e\n  \u003ch2\u003ePlatform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003ePortable Series (BF5–BF20)\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 #ddd;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eSingle or twin‑cylinder 4‑stroke, carbureted; manual or electric start; tiller or remote.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eBF5, BF8, BF9.9, BF15, BF20\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eLightweight, easy service access, excellent fuel economy.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCooling and fuel parts are model‑specific; verify shaft length and control type when selecting kits.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eMidrange Series (BF25–BF60)\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 #ddd;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInline‑3 4‑stroke, carbureted (earlier) or EFI\/PGM‑FI (later).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eBF25, BF30, BF40, BF50, BF60\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCompact design, strong mid‑range torque, low emissions.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eWater pump and thermostat service restores cooling performance; fuel system parts differ between carb and EFI versions—match by model\/serial.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eUpper Midrange Series (BF75–BF100)\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 #ddd;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInline‑4 4‑stroke, EFI\/PGM‑FI.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eBF75, BF90, BF100\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eSmooth operation, good fuel economy, robust alternator output for accessories.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eMany cooling and ignition items are shared across HP within a generation, but verify by model\/serial for exact fit.\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: 980px; margin: 0 auto; padding: 12px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines for Honda 4‑stroke outboards. Always follow the official service manual for your specific 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 #ddd;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEngine oil + filter\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInitial 20 hrs; then every 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eUse marine‑grade oil meeting OEM spec; replace filter each oil change.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/oil-filters\"\u003eOil Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect for water intrusion\/metal; renew seals if contamination found.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/honda-lower-unit-seal-kits\"\u003eHonda Lower Unit Seal Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect 100 hrs; replace 300 hrs or as needed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eGap to spec; replace if fouled or worn.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/honda-outboard-parts\"\u003eHonda Outboard Parts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eFuel filter \/ water‑separating filter\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eReplace sooner with ethanol fuel or dirty fuel supply.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect annually; replace every 2 seasons\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEssential for cooling; replace immediately if stream is weak or intermittent.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/honda-water-pump-repair-kits\"\u003eHonda Water Pump Repair Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAnodes (sacrificial)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect every 50–100 hrs; replace when 50% consumed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eUse the correct material (aluminum, zinc, or magnesium) for your water type.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eThermostat\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 2–3 years\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eReplace if overheat alarms or inconsistent running temperature occur.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/honda-outboard-parts\"\u003eHonda Outboard Parts\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: 980px; margin: 0 auto; padding: 12px;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service: \u003ca href=\"https:\/\/seasierra.com\/collections\/oil-filters\"\u003eOil Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System: \u003ca href=\"https:\/\/seasierra.com\/collections\/honda-water-pump-repair-kits\"\u003eHonda 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\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\u003eGearcase Seals \u0026amp; Gaskets: \u003ca href=\"https:\/\/seasierra.com\/collections\/honda-lower-unit-seal-kits\"\u003eHonda Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection: \u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropulsion \u0026amp; Accessories: \u003ca href=\"https:\/\/seasierra.com\/collections\/propellers\"\u003ePropellers\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"max-width: 980px; margin: 0 auto; padding: 12px;\"\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 #ddd;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eWeak tell‑tale stream \/ overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect intake screen for debris; verify pump housing and impeller condition; confirm thermostat operation.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eWater pump repair kit, impeller, thermostat, intake screen\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003ePoor acceleration \/ power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCheck fuel quality, replace fuel filter, confirm primer bulb stays firm, inspect prop for damage\/cavitation.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eFuel filter, fuel pump, spark plugs, propeller\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eDrain stale fuel, verify choke\/EFI operation, check for vacuum leaks, inspect\/replace spark plugs.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eSpark plugs, fuel filter, fuel pump, intake gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eGearcase noise or milky gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCheck oil level\/condition; look for water intrusion; pressure test and renew propshaft\/driveshaft seals if needed.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eLower unit seal kit, bearings, gear lube\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: 980px; margin: 0 auto; padding: 12px;\"\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 items cross over within a generation (for example, cooling or ignition components within the same BF series). However, updates in model codes, EFI vs carburetion, and shaft\/control options affect fit. Always match by full model and serial number.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the impeller on my Honda 4‑stroke?\u003c\/summary\u003e\n    \u003cp\u003eInspect annually and replace every two seasons as preventative maintenance. Replace immediately if the tell‑tale stream is weak, intermittent, or the engine triggers an overheat alarm.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should lower unit gear oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eChange every 100 hours or annually, and any time water contamination is found. If water intrusion is present, pressure test the gearcase and renew seals.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information helps confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide the full model (e.g., BF50D), serial number, shaft length (S\/L\/X), control type (tiller\/remote), and whether the engine is carbureted or EFI. Photos of the nameplate and the current part also help.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"max-width: 980px; margin: 0 auto; padding: 16px 12px;\"\u003e\n  \u003cp\u003eReady to find parts by horsepower, year, and model? Browse our complete Honda catalog to locate compatible components for your 5–100HP 4‑stroke outboard.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/honda-outboard-parts\" style=\"display:inline-block;background:#0a6efd;color:#fff;padding:10px 14px;border-radius:6px;text-decoration:none;\"\u003eShop Honda Outboard Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px;color:#444;\"\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-kit-fits-honda-outboard-bf5-bf100-replaces-19300-881-761-18-3627","title":"Honda Marine Outboard Thermostat, 125°F\/52°C – Fits BF5A, BF8A, BF9.9, BF15A, BF50F, BF75E\/F and BF100E\/F (Replaces 19300-881-761, Sierra 18-3627)","description":"\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 \u003cstrong\u003eHonda Marine outboard thermostat\u003c\/strong\u003e is a replacement thermostat designed for the Honda BF-series models listed below. It is specified to maintain an operating temperature of \u003cstrong\u003e125°F\/52°C\u003c\/strong\u003e and replaces Honda reference \u003cstrong\u003e19300-881-761\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThe thermostat is also cross-referenced with \u003cstrong\u003eSierra 18-3627\u003c\/strong\u003e. Use the model information and part-number references below to verify compatibility before ordering.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eReplacement thermostat for selected Honda marine outboard engines.\u003c\/li\u003e\n\u003cli\u003eSpecified operating temperature: 125°F\/52°C.\u003c\/li\u003e\n\u003cli\u003eDesigned for installation in the engine thermostat or cylinder-head cooling-system application, depending on model.\u003c\/li\u003e\n\u003cli\u003eThis listing is for the thermostat itself; gaskets, seals, bolts and other installation hardware are not included unless separately stated by the seller.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eThese are the documented manufacturer and aftermarket reference numbers associated with this thermostat.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003ePart Number\u003c\/th\u003e\n        \u003cth\u003eReference Type\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n        \u003ctd\u003eOEM reference\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3627\u003c\/td\u003e\n        \u003ctd\u003eAftermarket cross-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 company fitment record identifies the following Honda BF-series models for this thermostat. Model suffixes and serial-number conditions can affect fitment, so compare the original thermostat and the engine service-manual application 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\u003eCompatible Model\u003c\/th\u003e\n        \u003cth\u003eEngine Type\u003c\/th\u003e\n        \u003cth\u003eOEM Reference\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF5A1, BF5A2, BF5A3, BF5A4, BF5A5, BF5A6, BF5AH, BF5AK, BF5AK0, BF5AM, BF5AW, BF5AX, BF5AY\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF8A3, BF8A4, BF8A5, BF8A6, BF8AH, BF8AK, BF8AK0, BF8AM, BF8AW, BF8AX, BF8AY\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF9.9AH, BF9.9AK, BF9.9AM, BF9.9AW, BF9.9AX, BF9.9AY\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF15A1, BF15A2, BF15AH, BF15AK, BF15AM, BF15AW, BF15AX, BF15AY\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF50F\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF75E, BF75F\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eBF100E, BF100F\u003c\/td\u003e\n        \u003ctd\u003eBF-series marine outboard\u003c\/td\u003e\n        \u003ctd\u003e19300-881-761\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\u003eMarine outboard engine thermostat\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eSelected Honda BF-series outboard engines\u003c\/dd\u003e\n  \u003cdt\u003eOperating Temperature\u003c\/dt\u003e\n  \u003cdd\u003e125°F\/52°C\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n  \u003cdd\u003eReplacement thermostat in the model-specific thermostat or cooling-system application\u003c\/dd\u003e\n  \u003cdt\u003eHonda Reference\u003c\/dt\u003e\n  \u003cdd\u003e19300-881-761\u003c\/dd\u003e\n  \u003cdt\u003eSierra Reference\u003c\/dt\u003e\n  \u003cdd\u003e18-3627\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 x Replacement thermostat\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e The matching company product record identifies this product as a single thermostat rather than a multi-piece kit. Gaskets, rubber seal rings and other installation parts are not included in this listing unless specifically shown or stated with the order.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eConfirm the engine model, suffix and existing thermostat reference before beginning work.\u003c\/li\u003e\n\u003cli\u003eTurn the engine off and allow it to cool completely. Follow the engine manufacturer's safety instructions.\u003c\/li\u003e\n\u003cli\u003eLocate the thermostat according to the service manual for the specific Honda BF model.\u003c\/li\u003e\n\u003cli\u003eRemove the thermostat cover or related retaining components carefully, preserving the orientation of the original thermostat.\u003c\/li\u003e\n\u003cli\u003eRemove the old thermostat and inspect the cover, sealing surfaces and related hardware for corrosion or damage.\u003c\/li\u003e\n\u003cli\u003eClean the mating surfaces without scratching them. Replace any gasket or seal that the service manual identifies as non-reusable; replacement gaskets are not included with this thermostat.\u003c\/li\u003e\n\u003cli\u003eInstall the new thermostat in the correct orientation and reassemble the cover using the manufacturer's specified torque.\u003c\/li\u003e\n\u003cli\u003eRun the engine according to the service procedure and check for leaks and correct cooling-system operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003eInstallation procedures and required seals vary by model. Consult the appropriate Honda service manual or use a qualified marine technician when required.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I confirm that this thermostat fits my Honda outboard?\u003c\/summary\u003e\n  \u003cp\u003eMatch your complete engine model and suffix against the compatibility table, then compare the original part number with Honda reference 19300-881-761 or the Sierra cross-reference 18-3627. If the model suffix or serial range differs, consult the engine service manual before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are common signs of a failing thermostat?\u003c\/summary\u003e\n  \u003cp\u003eA faulty thermostat may contribute to overheating, delayed warm-up, operation below the intended temperature or unstable temperature behavior. Cooling-system restrictions and other faults can produce similar symptoms, so inspect the complete system before replacing parts.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the thermostat operating temperature?\u003c\/summary\u003e\n  \u003cp\u003eThe product record specifies an operating temperature of 125°F\/52°C.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDoes this listing include a gasket or rubber seals?\u003c\/summary\u003e\n  \u003cp\u003eNo. This listing is for one thermostat. Gaskets, rubber seal rings and other installation hardware are not included unless specifically stated in the order details.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eCan I install this thermostat myself?\u003c\/summary\u003e\n  \u003cp\u003eInstallation may be straightforward for an experienced marine mechanic, but the correct procedure, orientation, sealing method and torque specifications vary by engine model. Use the applicable service manual or seek professional installation.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM Honda thermostat?\u003c\/summary\u003e\n  \u003cp\u003eThis listing is a replacement product referenced against Honda part number 19300-881-761 and Sierra 18-3627. It is not presented as a genuine Honda-branded part.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat should I check before installation?\u003c\/summary\u003e\n  \u003cp\u003eVerify the complete engine model and suffix, compare the original thermostat and reference number, inspect the thermostat cover and sealing surfaces, and obtain any model-specific gasket or seal required for reassembly.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003c\/section\u003e\n\u003csection\u003e\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eWork only on a completely cool engine and follow all applicable marine-engine safety procedures.\u003c\/li\u003e\n\u003cli\u003eVerify the model, suffix and part reference before purchase; similar Honda BF models may use different cooling-system parts.\u003c\/li\u003e\n\u003cli\u003eDo not operate the engine if the thermostat cover leaks or if the cooling system does not function correctly after installation.\u003c\/li\u003e\n\u003cli\u003eThis product listing is for one replacement thermostat and does not include a gasket, seal ring or other hardware unless separately specified.\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 Parts Focus\u003c\/strong\u003e — We supply replacement components for outboard maintenance and repair applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment-Focused Listings\u003c\/strong\u003e — Product pages provide documented model and part-number references to help customers compare replacement parts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupport for Installation Planning\u003c\/strong\u003e — Always confirm the complete engine model and consult the applicable service information before beginning repairs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723979198779,"sku":"23TH614","price":26.4,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Thermostat_Kit_for_Honda_Outboard_Motor_4_Stroke_BF5_to_BF100_50-52C_19300-881-761_______19300-881-761_19351-ZV4-610_-_JLM_MARINE-8291327.jpg?v=1763039159"}],"url":"https:\/\/seasierra.com\/collections\/honda-4-stroke-5-100hp-outboard-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}