{"title":"Evinrude 2-Stroke 9.9-300HP Outboard Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px; border:1px solid #e5e7eb; border-radius:8px;\"\u003e\n  \u003cp\u003eThis page covers Evinrude 2-Stroke 9.9–300HP outboard engines and helps you find compatible parts and service information. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Johnson\/Evinrude collection. To start browsing parts for this engine, scroll to the bottom of the page. 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\/johnson-evinrude\" style=\"display:inline-block; padding:10px 16px; background:#0d6efd; color:#fff; text-decoration:none; border-radius:6px;\"\u003eBrowse All Johnson\/Evinrude Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"margin-top:24px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 9.9–300HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the nameplate: Evinrude model\/serial labels are typically on the transom bracket. The label shows the model code and a build date (month\/year).\u003c\/li\u003e\n    \u003cli\u003eRead the model code: Common elements include brand (E for Evinrude), horsepower (e.g., 9.9, 115, 300), feature letters (e.g., H for Lightning gearcase, C for counter rotation, D for E‑TEC direct injection), and a suffix indicating shaft length (L=20\", X=25\", Z=30\").\u003c\/li\u003e\n    \u003cli\u003eConfirm 2‑Stroke details: Determine if your engine is premix or oil‑injected. Some later 2‑Stroke models use direct injection (FICHT\/E‑TEC) and have specific fuel\/ignition components.\u003c\/li\u003e\n    \u003cli\u003eMatch platform: Smaller engines are typically inline twins, midrange are inline‑3, and larger models move to V4 and V6 platforms; parts such as gearcase, propellers, and ignition components often follow these platform families.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"platforms\" style=\"margin-top:24px;\"\u003e\n  \u003ch2\u003eEngine Platform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003eInline‑2 (9.9–15 HP)\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;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline‑2 carbureted 2‑Stroke; light and simple with tiller or remote options.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003e9.9HP\/15HP 2‑Stroke families (e.g., E10\/E15 series with L\/X\/Z shaft options).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eLow weight, easy maintenance, strong low‑speed control.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eCheck premix vs oil injection, idle mixture, and water pump service intervals.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eInline‑3 (25–75 HP)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse; margin-top:12px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline‑3 2‑Stroke; mostly carbureted with some direct‑injection variants in later years.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003e25\/30\/40\/50\/60\/70\/75 HP families across rope\/electric start and remote\/tiller control versions.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eGood mid‑range torque and broad parts availability.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eKeep fuel system clean; perform link‑and‑sync on carb models. DI versions use specific injectors and fuel pumps.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eV4 (90–140 HP)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse; margin-top:12px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eV4 2‑Stroke, carbureted and later DI options; 20–30 inch shafts.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003e90\/100\/115\/120\/130\/140 HP families (e.g., E115\/E130 series with L\/X\/Z shaft designations).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eStrong acceleration and broad propeller choices.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eMaintain cooling system (thermostats\/impeller). Gearcase and prop hardware vary by shaft length and rotation.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eV6 (150–300 HP)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse; margin-top:12px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eV6 2‑Stroke; many models feature direct injection (FICHT\/E‑TEC). Options include counter‑rotation and performance gearcases.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003e150\/175\/200\/225\/250\/275\/300 HP families; examples include 300 HP “H” gearcase variants (Lightning gearcase series).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eHigh output with strong top‑end performance; wide prop selection.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eVerify rotation and gearcase type when ordering props\/seals. DI engines require correct injector and fuel system components.\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=\"margin-top:24px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines for Evinrude 2‑Stroke outboards. Always follow the specific service schedule and procedures in your engine’s official service manual.\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;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003ePremix ratio \/ oil‑injection system\u003c\/td\u003e\n        \u003ctd\u003eEvery outing\u003c\/td\u003e\n        \u003ctd\u003eUse the correct mix (commonly 50:1 for premix models). Inspect oil tank, lines, and primer operation on injected models.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-hoses\"\u003eJohnson\/Evinrude\/OMC Hoses\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd\u003e100 hours or annually\u003c\/td\u003e\n        \u003ctd\u003eDrain and inspect for water\/metal. Replace seals if contamination is found.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-lower-unit-seal-kits\"\u003eJohnson\/Evinrude\/OMC Lower Unit Seal Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd\u003e100 hours or annually\u003c\/td\u003e\n        \u003ctd\u003eInstall the correct heat range and gap per the service manual.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plugs\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eFuel filter \/ water separator\u003c\/td\u003e\n        \u003ctd\u003e100 hours or annually\u003c\/td\u003e\n        \u003ctd\u003eReplace and check for debris or water; maintain clean fuel for DI engines.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd\u003eEvery 2–3 years (sooner in sandy\/silty or high‑use conditions)\u003c\/td\u003e\n        \u003ctd\u003eWeak tell‑tale or overheat alarms indicate service is due.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-water-pump-repair-kits\"\u003eJohnson\/Evinrude\/OMC Water Pump Repair Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAnodes (zinc\/aluminum\/magnesium)\u003c\/td\u003e\n        \u003ctd\u003eInspect every 50–100 hours\u003c\/td\u003e\n        \u003ctd\u003eReplace when 50% consumed; choose alloy for your water type (salt\/brackish\/fresh).\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-anodes\"\u003eJohnson\/Evinrude\/OMC Anodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003ePropeller and hub hardware\u003c\/td\u003e\n        \u003ctd\u003eEvery 100 hours or as needed\u003c\/td\u003e\n        \u003ctd\u003eRemove, inspect for fishing line and damage; torque to spec.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-propellers\"\u003eJohnson\/Evinrude\/OMC Propellers\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eThermostat(s)\u003c\/td\u003e\n        \u003ctd\u003eInspect annually\u003c\/td\u003e\n        \u003ctd\u003eOver‑cooling or overheat can indicate thermostat faults; replace as needed.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude\"\u003eJohnson\/Evinrude 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=\"margin-top:24px;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service Kits — \u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-service-maintenance-kits\"\u003eJohnson\/Evinrude\/OMC Service \u0026amp; Maintenance Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System — \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-water-pump-repair-kits\"\u003eWater Pump Repair Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase Seals — \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-lower-unit-seal-kits\"\u003eLower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropulsion — \u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-propellers\"\u003ePropellers\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\/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\u003eCorrosion Protection — \u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-anodes\"\u003eAnodes\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"margin-top:24px;\"\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;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eWeak tell‑tale or overheat alarm\u003c\/td\u003e\n        \u003ctd\u003eInspect intake screens, confirm strong tell‑tale, test thermostats; service the impeller if flow is weak.\u003c\/td\u003e\n        \u003ctd\u003eWater pump kit, thermostat(s), intake screen, anodes\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003ePoor acceleration or power loss\u003c\/td\u003e\n        \u003ctd\u003eCheck prop for damage\/slip, verify spark plug condition, replace fuel filter; ensure throttle opens fully.\u003c\/td\u003e\n        \u003ctd\u003ePropeller\/hub hardware, spark plugs, fuel filter, fuel pump diaphragm\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd\u003eVerify choke\/primer operation, look for air leaks in fuel lines, check plug gap; on carb models, clean and sync.\u003c\/td\u003e\n        \u003ctd\u003eSpark plugs, carburetor kit, fuel hoses, primer\/choke components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eExcessive smoke (2‑Stroke)\u003c\/td\u003e\n        \u003ctd\u003eNormal when cold; if persistent, recheck premix ratio or oil pump setting, and idle mixture.\u003c\/td\u003e\n        \u003ctd\u003eCarburetor kit, oil hoses, primer\/choke components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd\u003eDrain oil and inspect; pressure\/vacuum test. Replace worn seals before damage progresses.\u003c\/td\u003e\n        \u003ctd\u003eLower unit seal kit, drain\/fill seals, prop shaft hardware\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=\"margin-top:24px;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable across different years or platforms?\u003c\/summary\u003e\n    \u003cp\u003eSome components interchange within the same platform family (e.g., many V4 parts share across 90–140 HP), but changes in year, shaft length, rotation, and features (e.g., Lightning gearcase, direct injection) affect compatibility. Always confirm with the exact model code and serial.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the water pump impeller?\u003c\/summary\u003e\n    \u003cp\u003eAs preventive maintenance, every 2–3 years, or sooner for heavy use or sandy\/silty water. Replace immediately if tell‑tale flow is weak or if an overheat alarm occurs.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should I change the lower unit gear oil?\u003c\/summary\u003e\n    \u003cp\u003eInspect and change at least once per season or every 100 hours. If water or metal is found, service the seals and re‑test before further operation.\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\u003eProvide the model code and serial number from the transom bracket label, horsepower, shaft length (L\/X\/Z), rotation (standard or counter‑rotation), and any feature designations (e.g., H gearcase, DI\/E‑TEC). Photos of the nameplate and the part area help ensure a correct match.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"margin-top:24px; padding:16px; border:1px solid #e5e7eb; border-radius:8px;\"\u003e\n  \u003cp\u003eReady to find parts? Browse the Johnson\/Evinrude collection and refine by horsepower, year, and model to locate compatible components for your engine.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude\" style=\"display:inline-block; padding:10px 16px; background:#0d6efd; color:#fff; text-decoration:none; border-radius:6px;\"\u003eShop Johnson\/Evinrude Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px; color:#4b5563;\"\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-62-143-f-fits-johnson-evinrude-9-9-300hp-two-stroke-outboards-replaces-0778199-0394411","title":"143°F \/ 62°C Thermostat for Johnson\/Evinrude 2-Stroke Outboards – Replaces 0394411, 0778199","description":"\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\u003csection\u003e\n  \u003ch2\u003eProduct Details\u003c\/h2\u003e\n  \u003cp\u003eThis aftermarket \u003cstrong\u003e143°F \/ 62°C Vernatherm thermostat\u003c\/strong\u003e is designed for selected Johnson and Evinrude two-stroke outboards. It helps regulate engine operating temperature by opening at approximately 62°C (143°F) when the specified temperature is reached.\u003c\/p\u003e\n  \u003cp\u003eThe thermostat replaces the listed Johnson\/Evinrude\/OMC references \u003cstrong\u003e394411, 0394411, 778199, and 0778199\u003c\/strong\u003e. The company listing also identifies Sierra Marine \u003cstrong\u003e18-1506\u003c\/strong\u003e as an equivalent aftermarket reference.\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eAftermarket replacement thermostat for selected Johnson\/Evinrude outboards.\u003c\/li\u003e\n    \u003cli\u003e143°F \/ 62°C opening temperature.\u003c\/li\u003e\n    \u003cli\u003eSold as a single thermostat component, not as a multi-piece kit.\u003c\/li\u003e\n    \u003cli\u003eConfirm the complete engine model, year, stroke, and original thermostat reference before ordering.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n  \u003cp\u003eUse these references to compare the thermostat with the part installed on your engine. Part-number similarity alone does not confirm fitment.\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 or Reference\u003c\/th\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003c\/tr\u003e\n      \u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\/OMC\u003c\/td\u003e\n\u003ctd\u003e394411 \/ 0394411\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\/OMC\u003c\/td\u003e\n\u003ctd\u003e778199 \/ 0778199\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSierra Marine\u003c\/td\u003e\n\u003ctd\u003e18-1506\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eGLM\u003c\/td\u003e\n\u003ctd\u003e13190\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n  \u003cp\u003eThe following horsepower, stroke, and year combinations are listed for this thermostat. Verify the exact engine model and serial-number range in your service information 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\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eYears\u003c\/th\u003e\n\u003cth\u003eListed OEM Reference\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\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e10 \/ 15\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1993–1995\u003c\/td\u003e\n\u003ctd\u003e0394411 \/ 394411\u003c\/td\u003e\n\u003ctd\u003eBig Bore applications\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e60 \/ 125 \/ 185\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1989–1990\u003c\/td\u003e\n\u003ctd\u003e0394411 \/ 394411\u003c\/td\u003e\n\u003ctd\u003eUse only where the original thermostat reference matches\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e65\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1987–1989\u003c\/td\u003e\n\u003ctd\u003e0394411 \/ 394411\u003c\/td\u003e\n\u003ctd\u003eVerify the exact model before ordering\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e70 \/ 200 \/ 225\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1986–1990\u003c\/td\u003e\n\u003ctd\u003e0394411 \/ 394411\u003c\/td\u003e\n\u003ctd\u003eVerify the exact model before ordering\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e120 \/ 140 \/ 300\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1985–1990\u003c\/td\u003e\n\u003ctd\u003e0394411 \/ 394411\u003c\/td\u003e\n\u003ctd\u003eVerify the exact model before ordering\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e275\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1985–1988\u003c\/td\u003e\n\u003ctd\u003e0394411 \/ 394411\u003c\/td\u003e\n\u003ctd\u003eVerify the exact model before ordering\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n  \u003cp\u003eThe company reference also mentions Vernatherm applications for 65, 85, 100, 115, and 135 HP engines. Because complete year and model conditions are not provided for those additional references, confirm the original part number and service-manual application before purchase.\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n  \u003cdl\u003e\n    \u003cdt\u003eProduct Type\u003c\/dt\u003e\n    \u003cdd\u003eAftermarket outboard engine thermostat\u003c\/dd\u003e\n    \u003cdt\u003eThermostat Style\u003c\/dt\u003e\n    \u003cdd\u003eVernatherm-style thermostat\u003c\/dd\u003e\n    \u003cdt\u003eTemperature Rating\u003c\/dt\u003e\n    \u003cdd\u003e143°F \/ 62°C\u003c\/dd\u003e\n    \u003cdt\u003eOpening Temperature\u003c\/dt\u003e\n    \u003cdd\u003eApproximately 62°C (143°F)\u003c\/dd\u003e\n    \u003cdt\u003eEngine Type\u003c\/dt\u003e\n    \u003cdd\u003eSelected Johnson\/Evinrude two-stroke outboards\u003c\/dd\u003e\n    \u003cdt\u003eReplacement References\u003c\/dt\u003e\n    \u003cdd\u003e394411, 0394411, 778199, 0778199\u003c\/dd\u003e\n    \u003cdt\u003eAftermarket Reference\u003c\/dt\u003e\n    \u003cdd\u003eSierra Marine 18-1506\u003c\/dd\u003e\n    \u003cdt\u003eProduct Configuration\u003c\/dt\u003e\n    \u003cdd\u003eSingle thermostat component\u003c\/dd\u003e\n  \u003c\/dl\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cspan style=\"color:#d0021b;\"\u003e1\u003c\/span\u003e x 143°F \/ 62°C aftermarket thermostat\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \u003cp\u003eThis listing is for the thermostat component. Confirm whether your engine requires a separate gasket, seal, or other installation hardware before beginning the repair.\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n  \u003col\u003e\n    \u003cli\u003eSwitch off the engine, allow it to cool completely, and follow the safety procedures in the service manual.\u003c\/li\u003e\n    \u003cli\u003eDisconnect the battery if required by the manufacturer’s service procedure.\u003c\/li\u003e\n    \u003cli\u003eLocate the thermostat housing and note the orientation of the existing thermostat before removal.\u003c\/li\u003e\n    \u003cli\u003eRemove the housing cover carefully and take out the old thermostat and sealing components.\u003c\/li\u003e\n    \u003cli\u003eClean the mating surfaces without damaging the housing or cylinder-head sealing area.\u003c\/li\u003e\n    \u003cli\u003eInstall the replacement thermostat in the same orientation as the original part.\u003c\/li\u003e\n    \u003cli\u003eInstall the correct new gasket or seal if required for your specific engine. Do not reuse damaged sealing components.\u003c\/li\u003e\n    \u003cli\u003eReinstall the thermostat cover and tighten the fasteners to the manufacturer’s specified torque.\u003c\/li\u003e\n    \u003cli\u003eRestore the cooling-system configuration, start the engine according to the service manual, and check for leaks and normal water flow.\u003c\/li\u003e\n    \u003cli\u003eStop the engine immediately if it overheats, leaks, or shows abnormal temperature behavior.\u003c\/li\u003e\n  \u003c\/ol\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat does this thermostat do?\u003c\/summary\u003e\n    \u003cp\u003eIt controls coolant or cooling-water flow through the outboard’s cooling system to help the engine reach and maintain its specified operating temperature. This model is listed with a 143°F \/ 62°C opening temperature.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhich engines does it fit?\u003c\/summary\u003e\n    \u003cp\u003eIt is listed for selected Johnson\/Evinrude two-stroke applications, including the horsepower and year combinations shown in the compatibility table. Always verify the complete model and original part number because engines with the same horsepower rating may use different components.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this thermostat for four-stroke engines?\u003c\/summary\u003e\n    \u003cp\u003eNo four-stroke applications are identified for this listing. It is intended for the specified Johnson\/Evinrude two-stroke applications only.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes the listing include a gasket?\u003c\/summary\u003e\n    \u003cp\u003eThe company record identifies this product as a single thermostat component and does not specify a gasket in the package contents. Check your engine’s parts diagram and obtain the correct gasket or seal separately if required.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow can I tell if my thermostat needs replacement?\u003c\/summary\u003e\n    \u003cp\u003ePossible symptoms include overheating, running below the normal operating temperature, slow warm-up, or inconsistent temperature behavior. Inspect the thermostat and cooling passages according to the engine service manual before replacing parts.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eCan I install it myself?\u003c\/summary\u003e\n    \u003cp\u003eThermostat replacement may be suitable for an experienced owner with the correct tools and service information. If you are uncertain about the thermostat orientation, sealing procedure, or torque specifications, use a qualified marine technician.\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 listed to replace the referenced Johnson\/Evinrude\/OMC part numbers and cross-reference numbers.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection\u003e\n  \u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eVerify the exact engine model, year, stroke, serial-number range, and original thermostat reference before ordering.\u003c\/li\u003e\n    \u003cli\u003eDo not rely on horsepower alone to confirm compatibility.\u003c\/li\u003e\n    \u003cli\u003eNever work on a hot engine or open the thermostat housing before the engine has cooled.\u003c\/li\u003e\n    \u003cli\u003eUse the manufacturer’s service manual for installation orientation, gasket requirements, torque values, and cooling-system checks.\u003c\/li\u003e\n    \u003cli\u003eThis is an aftermarket replacement component, not an original manufacturer part.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\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 — We provide aftermarket components for common marine repair and maintenance applications.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Product references and fitment details are provided to help you compare the replacement part with your original component.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVerify Before Installation\u003c\/strong\u003e — Always compare the part number, physical design, and engine application with your service information before fitting a replacement part.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723987652923,"sku":"23TH624","price":20.9,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/23TH624_1_84ded38a-ff91-40fb-a92a-7d090609e746.jpg?v=1763039535"}],"url":"https:\/\/seasierra.com\/collections\/evinrude-2-stroke-9-9-300hp-outboard-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}