{"title":"OMC 8.1L 4-Stroke Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px; border:1px solid #e5e7eb; border-radius:8px;\"\u003e\n  \u003cp\u003eThis page is for OMC 8.1L 4‑Stroke marine engines. Use it to find compatible parts and service information, including maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Johnson\/Evinrude\/OMC collection for broader coverage. Scroll to the bottom of this page to start browsing parts for this engine. 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-omc-outboard-parts\" style=\"display:inline-block; padding:10px 14px; background:#0ea5e9; color:#fff; text-decoration:none; border-radius:6px;\"\u003eBrowse All OMC\/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 8.1L Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the serial\/nameplate on the engine block (often on a rocker cover or intake area) and on the transom assembly or drive for sterndrive installations.\u003c\/li\u003e\n    \u003cli\u003eDecode the model\/serial details to confirm drive type (inboard shaft vs. sterndrive), cooling type (raw-water or closed cooling), and approximate build year\/series.\u003c\/li\u003e\n    \u003cli\u003eFor 4‑stroke EFI packages, note the ECM\/MEFI label and calibration tag; this helps match ignition, sensors, and fuel-system parts.\u003c\/li\u003e\n    \u003cli\u003eCheck the seawater pump style and impeller dimensions; sterndrive packages often use a crankshaft‑driven raw-water pump, while inboards may vary by cooling configuration.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"margin-top:24px;\"\u003e\n  \u003ch2\u003eEngine\/Platform Overview\u003c\/h2\u003e\n  \u003ch3\u003eSterndrive Installation (Transom‑Mounted Drive)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e8.1L V8, multi‑port EFI, 4‑stroke; raw‑water or closed‑cooling options; seawater pump supplies heat exchanger or block.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e8.1L sterndrive packages used in various OMC‑equipped boats; verify by engine + drive serials.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eHigh torque for planing and cruising; broad parts support; straightforward seasonal servicing.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eImpeller located in the seawater pump; ensure anode material matches water type and drive housing; service gearcase oil and seals as part of seasonal maintenance.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eInboard Installation (Shaft Drive)\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; padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e8.1L V8, multi‑port EFI, 4‑stroke; typically with heat exchanger and raw‑water pump feeding the system.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e8.1L inboard packages across cruisers and towboats; confirm by engine serial and cooling layout.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eRobust torque and durability; easy access to many service items; compatible with common EFI diagnostics.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eVerify impeller size and pump style; exhaust manifolds\/risers are wear items in saltwater; closed‑cooling increases component life when maintained.\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 typical use. Always follow your official service manual and adjust intervals for heavy duty or saltwater operation.\u003c\/p\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eEngine oil + filter\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eUse marine‑grade oil; warm engine before draining; replace crush washer\/seal if applicable.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\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:8px; border-bottom:1px solid #f3f4f6;\"\u003eGear oil (sterndrive)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eInspect for water or metal; replace drain screw gaskets; service seals if contamination is found.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/service-maintenance-kits\"\u003eService \u0026amp; Maintenance Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eInspect at 100 hrs; replace ~300 hrs\/3 yrs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eCheck gap and heat range per manual; replace sooner if fouling\/misfire occurs.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\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 #f3f4f6;\"\u003eFuel filter \/ water‑separating filter\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eDrain bowl (if equipped) and replace element; keep spare aboard for contamination events.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\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 #f3f4f6;\"\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e2–3 seasons or ~300 hrs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eReplace sooner if stream is weak, temps rise, or impeller shows set\/wear.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\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 style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eAnodes (engine \u0026amp; drive)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eInspect every 100 hrs; replace when 50% depleted\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eMatch anode material to water (zinc–salt, aluminum–brackish, magnesium–freshwater).\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\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 style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eSerpentine\/accessory belt\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eInspect each season; replace if cracked\/noisy\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eCheck tensioner and idler bearings; carry a spare aboard.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/belt\"\u003eBelts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eExhaust manifolds\/risers\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect annually; replace 3–5 yrs (saltwater)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eMonitor for corrosion, leaks, and overheating signs; replace gaskets\/hardware as needed.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/manifolds\"\u003eManifolds\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: \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\"\u003eJohnson\/Evinrude\/OMC Water Pump Repair Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection: \u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-anodes\"\u003eJohnson\/Evinrude\/OMC Anodes\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\/starters\"\u003eStarters\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/alternators\"\u003eAlternators\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eExhaust Components: \u003ca href=\"https:\/\/seasierra.com\/collections\/manifolds\"\u003eManifolds\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropellers \u0026amp; Hardware: \u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-propellers\"\u003eJohnson\/Evinrude\/OMC Propellers\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; padding:8px;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #e5e7eb; padding:8px;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eWeak water stream or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eInspect intake screens for blockages; verify impeller condition and hose clamps; confirm thermostat operation.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eWater pump kit, intake screen\/strainer, thermostat, hoses\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003ePoor acceleration or power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eCheck prop condition\/pitch; replace fuel filter; test fuel pressure; inspect plugs and plug wires.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003ePropeller, fuel filter, spark plugs, ignition components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eHard starting or rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eLook for air leaks at fuel fittings; check IAC\/idle air passages; verify sensor connections and vacuum lines.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eSpark plugs, fuel filter, sensors, gaskets\/hoses\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eGearcase noise or metal in gear oil (sterndrive)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eCheck for water intrusion; inspect prop shaft seals and magnetic drain plug; service bearings if noise persists.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px; border-bottom:1px solid #f3f4f6;\"\u003eLower unit seals, bearings, prop shaft seals, gear oil\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eBelt squeal or charging issues\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect serpentine belt wear and tensioner; verify alternator pulley alignment.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eBelt, tensioner pulley, alternator\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 8.1L parts interchangeable across different years or between inboard and sterndrive installs?\u003c\/summary\u003e\n    \u003cp\u003eNot always. Cooling layout, ECM\/MEFI calibration, accessory brackets, and drive components can change by year and installation type. Confirm with your engine and (if applicable) drive serials before ordering.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the raw‑water impeller?\u003c\/summary\u003e\n    \u003cp\u003eInspect annually and replace about every 2–3 seasons or ~300 hours, sooner if you see weak water flow, rising temperatures, or impeller vane set\/cracking.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should sterndrive gear oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eTypically every 100 hours or annually. Always check for water or metallic debris when draining; contamination indicates seals or components may need service.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information helps confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide engine serial\/model, installation type (inboard vs. sterndrive), cooling type (raw vs. closed), and clear photos of the nameplate and the part you are replacing.\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 shop? Browse the main Johnson\/Evinrude\/OMC collection by model and year, then use the page filters to refine by category.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-outboard-parts\" style=\"display:inline-block; margin-top:8px; padding:10px 14px; background:#0ea5e9; color:#fff; text-decoration:none; border-radius:6px;\"\u003eShop OMC\/Johnson\/Evinrude Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px; color:#374151;\"\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-volvo-penta-4-3l-8-2l-omc-cobra-4-3l-5-8l-replaces-0769578-3853983-3852111-0986506","title":"140°F Thermostat Kit for OMC Cobra and Volvo Penta 7.4L \u0026 8.2L – Replaces 3853983, 0769578, 0986506","description":"\u003cstyle\u003e\n\/* Outer container allows horizontal scrolling (with iOS momentum) *\/\n.ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n\/* Base table styles *\/\ntable.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\ntable.ss-table th, table.ss-table td { padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top; }\ntable.ss-table th { white-space:nowrap; word-break:normal; letter-spacing:normal; font-weight:600; background:#f8fafc; }\n\/* Small screen optimization *\/\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 140°F (60°C) aftermarket thermostat kit is designed for specified OMC Cobra stern-drive and Volvo Penta stern-drive applications. The documented fitment is limited to 7.4L engines from 1994–1998 and 8.2L engines from 1998. Confirm the engine model, year, original thermostat temperature, and part numbers before ordering.\u003c\/p\u003e\n\u003cp\u003eThe kit replaces the thermostat reference 3853983 and is listed with OMC and Volvo Penta reference numbers 0769578 and 0986506. Sierra Marine 18-3676 is the corresponding 140°F thermostat kit reference.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e140°F (60°C) thermostat opening temperature.\u003c\/li\u003e\n\u003cli\u003eAftermarket replacement for the specified marine stern-drive cooling applications.\u003c\/li\u003e\n\u003cli\u003eKit includes the thermostat, thermostat gasket, and O-ring.\u003c\/li\u003e\n\u003cli\u003eComponent references are provided for identification and fitment verification.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse the references below to compare the replacement kit with the part installed on your engine. Part-number references do not replace verification of the complete model and year application.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n\u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eReference type\u003c\/th\u003e\n\u003cth\u003ePart number\u003c\/th\u003e\n\u003cth\u003eDescription\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC \/ Volvo Penta reference\u003c\/td\u003e\n\u003ctd\u003e3853983\u003c\/td\u003e\n\u003ctd\u003e140°F thermostat reference\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Cobra reference\u003c\/td\u003e\n\u003ctd\u003e0769578\u003c\/td\u003e\n\u003ctd\u003eThermostat kit reference listed by the company catalog\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Cobra reference\u003c\/td\u003e\n\u003ctd\u003e0986506\u003c\/td\u003e\n\u003ctd\u003eThermostat kit reference listed by the company catalog\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra Marine reference\u003c\/td\u003e\n\u003ctd\u003e18-3676\u003c\/td\u003e\n\u003ctd\u003e140°F thermostat kit reference\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermostat component\u003c\/td\u003e\n\u003ctd\u003e3853983\u003c\/td\u003e\n\u003ctd\u003eThermostat included in the kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGasket component\u003c\/td\u003e\n\u003ctd\u003e3852111\u003c\/td\u003e\n\u003ctd\u003eThermostat gasket included in the kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eO-ring component\u003c\/td\u003e\n\u003ctd\u003e3852071\u003c\/td\u003e\n\u003ctd\u003eO-ring included in the kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe following applications are documented for this 140°F thermostat kit. Do not extend these applications to other engine sizes, years, or thermostat temperatures without confirming the applicable service information.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n\u003ctable class=\"ss-table\" aria-label=\"Engine Compatibility\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand \/ drive type\u003c\/th\u003e\n\u003cth\u003eEngine\u003c\/th\u003e\n\u003cth\u003eYears\u003c\/th\u003e\n\u003cth\u003eStroke\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\u003eOMC Cobra stern drive\u003c\/td\u003e\n\u003ctd\u003e7.4L V8\u003c\/td\u003e\n\u003ctd\u003e1994–1998\u003c\/td\u003e\n\u003ctd\u003e4-Stroke gasoline\u003c\/td\u003e\n\u003ctd\u003e140°F thermostat kit application\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVolvo Penta stern drive\u003c\/td\u003e\n\u003ctd\u003e7.4 GL, 7.4 Gi, 7.4 GSi\u003c\/td\u003e\n\u003ctd\u003eVerify by engine model and year\u003c\/td\u003e\n\u003ctd\u003e4-Stroke gasoline\u003c\/td\u003e\n\u003ctd\u003eCompany-listed model family; confirm the original part before purchase\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Cobra \/ Volvo Penta stern drive\u003c\/td\u003e\n\u003ctd\u003e8.2L V8\u003c\/td\u003e\n\u003ctd\u003e1998\u003c\/td\u003e\n\u003ctd\u003e4-Stroke gasoline\u003c\/td\u003e\n\u003ctd\u003e140°F thermostat kit application\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVolvo Penta stern drive\u003c\/td\u003e\n\u003ctd\u003e8.2 GL, 8.2 GSi\u003c\/td\u003e\n\u003ctd\u003eVerify by engine model and year\u003c\/td\u003e\n\u003ctd\u003e4-Stroke gasoline\u003c\/td\u003e\n\u003ctd\u003eCompany-listed model family; confirm the original part before purchase\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e The available catalog evidence specifically identifies the 7.4L application as 1994–1998 and the 8.2L application as 1998. The kit should not be described as fitting all 4.3L, 5.0L, 5.7L, 5.8L, 8.1L, or 8.2L engines without an applicable model-specific confirmation.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cdl\u003e\n\u003cdt\u003eProduct type\u003c\/dt\u003e\n\u003cdd\u003eThermostat kit\u003c\/dd\u003e\n\u003cdt\u003eThermostat temperature\u003c\/dt\u003e\n\u003cdd\u003e140°F \/ 60°C opening temperature\u003c\/dd\u003e\n\u003cdt\u003eApplication\u003c\/dt\u003e\n\u003cdd\u003eMarine gasoline stern-drive cooling systems\u003c\/dd\u003e\n\u003cdt\u003eReplacement type\u003c\/dt\u003e\n\u003cdd\u003eAftermarket replacement\u003c\/dd\u003e\n\u003cdt\u003ePrimary thermostat reference\u003c\/dt\u003e\n\u003cdd\u003e3853983\u003c\/dd\u003e\n\u003cdt\u003eDocumented engine range\u003c\/dt\u003e\n\u003cdd\u003e7.4L, 1994–1998; 8.2L, 1998\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 × 140°F (60°C) thermostat\u003c\/li\u003e\n\u003cli\u003e1 × thermostat gasket, reference 3852111\u003c\/li\u003e\n\u003cli\u003e1 × O-ring, reference 3852071\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe included gasket and O-ring are kit components. Their availability as separate replacement parts does not change the package contents of this thermostat kit.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eAllow the engine to cool completely and disconnect the battery before starting work.\u003c\/li\u003e\n\u003cli\u003eClose or isolate the applicable cooling-water and coolant sources according to the engine manufacturer's service procedure.\u003c\/li\u003e\n\u003cli\u003eRemove the thermostat housing cover and note the installed thermostat orientation.\u003c\/li\u003e\n\u003cli\u003eRemove the old thermostat, gasket, and O-ring. Clean the mating surfaces without damaging the housing.\u003c\/li\u003e\n\u003cli\u003eInstall the new thermostat in the same orientation as the original component.\u003c\/li\u003e\n\u003cli\u003eFit the supplied gasket and O-ring in the locations specified for your engine model.\u003c\/li\u003e\n\u003cli\u003eReinstall the housing cover and tighten fasteners to the engine manufacturer's specified torque.\u003c\/li\u003e\n\u003cli\u003eRestore the cooling system, start the engine, and check for leaks and abnormal temperature behavior.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003eInstallation procedures can vary between engine models. Use the applicable factory service information for torque values, coolant draining, refill, and bleeding procedures.\u003c\/p\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat temperature does this thermostat open at?\u003c\/summary\u003e\n\u003cp\u003eThis kit is listed as a 140°F (60°C) thermostat kit. Verify that your engine requires this temperature before installation.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhich engines are documented for this kit?\u003c\/summary\u003e\n\u003cp\u003eThe company catalog documents 7.4L applications from 1994–1998 and 8.2L applications from 1998. It also lists Volvo Penta 7.4 GL, 7.4 Gi, 7.4 GSi, 8.2 GL, and 8.2 GSi model families. Confirm the exact engine model, year, and original part number.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat parts are included?\u003c\/summary\u003e\n\u003cp\u003eThe kit includes one thermostat, one thermostat gasket, and one O-ring. The component references are thermostat 3853983, gasket 3852111, and O-ring 3852071.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs this an OEM thermostat?\u003c\/summary\u003e\n\u003cp\u003eNo. This listing is for an aftermarket replacement kit. The OEM and aftermarket reference numbers are supplied for identification and compatibility comparison only.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use this kit on a 4.3L, 5.0L, 5.7L, or 5.8L engine?\u003c\/summary\u003e\n\u003cp\u003eThose applications are not confirmed for this specific kit by the company record used for this listing. Match your exact engine model, year, thermostat temperature, and original part number before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat are common signs of a thermostat problem?\u003c\/summary\u003e\n\u003cp\u003ePossible symptoms include overheating, an engine that runs unusually cool, unstable temperature readings, or coolant leakage near the thermostat housing. Diagnose the complete cooling system before replacing the thermostat.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eWork only on a cool engine and follow the applicable marine engine service procedure.\u003c\/li\u003e\n\u003cli\u003eDo not rely on engine size alone for fitment; verify model, year, thermostat temperature, and original part number.\u003c\/li\u003e\n\u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n\u003cli\u003eProfessional installation is recommended when the cooling-system procedure or engine-specific requirements are uncertain.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMarine Parts Support\u003c\/strong\u003e — We provide replacement components for marine maintenance and repair applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment-Focused Listings\u003c\/strong\u003e — Product references and documented applications are presented to help customers verify compatibility.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePractical Replacement Solutions\u003c\/strong\u003e — Aftermarket components are offered for routine marine service needs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723970744635,"sku":"23TH018","price":30.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Thermostat_Kit_for_Volvo_Penta_43L_50L_57L_74L_81L_0769578_3853983_3852111___________3853983_-_JLM_MARINE-8291118.jpg?v=1763038813"}],"url":"https:\/\/seasierra.com\/collections\/omc-8-1l-4-stroke-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}