{"title":"OMC 4-Stroke 7.4L Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px; border:1px solid #e5e7eb; border-radius:8px;\"\u003e\n  \u003cp\u003e\n    This page is dedicated to OMC 4‑Stroke 7.4L marine engines. It helps you find compatible parts and service information, with maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main OMC collection. Scroll to the bottom of the page to start browsing parts for this engine, and remember that on the collection page you can use the Filter \u0026amp; Sort controls to narrow results by horsepower, year range, and part category.\n  \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 Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"padding:16px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 7.4L Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the identification\/serial plate on the engine (typically near the bellhousing or intake manifold area) and the drive\/transom bracket. Photograph both tags for reference.\u003c\/li\u003e\n    \u003cli\u003eModel codes and build sheets may indicate engine generation (Gen IV\/V\/VI), cam type (flat tappet vs. roller), rotation (LH vs. RH), and head style (oval vs. rectangular port). These details affect gasket sets, cam\/lifter style, and seals.\u003c\/li\u003e\n    \u003cli\u003eGeneration cues: older Gen IV engines commonly use a 2‑piece rear main seal and flat tappet cams; later Gen V\/VI typically use a 1‑piece rear main seal and roller valvetrain. Matching the generation is critical for parts compatibility.\u003c\/li\u003e\n    \u003cli\u003eFor sterndrive cooling systems, note whether the raw‑water pump is in the drive (impeller kit) or belt‑driven on the engine. This determines which water pump parts you need.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"padding:16px;\"\u003e\n  \u003ch2\u003eEngine Overview\u003c\/h2\u003e\n\n  \u003ch3\u003e7.4L (454 cu in) Gen IV V8 — approx. 1970s–1990\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;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eGM big‑block V8, carbureted in most marine builds; often flat tappet cam; many with 2‑piece rear main seal\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003e7.4L\/454 marine V8 with oval or rectangular port heads; standard or reverse rotation variants\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eAbundant torque and broad parts availability\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eGaskets, cam\/lifters, and seal kits differ from later generations; verify head style and rotation before ordering\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003e7.4L (454 cu in) Gen V V8 — approx. 1991–1997\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;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eV8 big‑block with 1‑piece rear main seal; many marine builds use roller valvetrain components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003e7.4L\/454 marine V8, typically oval‑port heads; carbureted or EFI depending on marinizer\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eImproved sealing and compatibility with later gasket sets; strong mid‑range torque\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eGasket sets and cam\/lifter style are not interchangeable with Gen IV; confirm generation from serial\/model data\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003e7.4L (454 cu in) Gen VI V8 — approx. late 1990s–early 2000s\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;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eV8 big‑block, roller cam, 1‑piece rear main seal; many EFI applications; marine‑specific cooling and ignition components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003e7.4L\/454 marine V8 (roller cam), often EFI; versions may differ in accessory brackets and sensors\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eRefined reliability, easier sealing, and strong parts support\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eUse generation‑correct gasket and timing sets; verify sensor and timing cover style when ordering\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"service-kits\" style=\"padding:16px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general marine guidelines. Always follow your official service manual for your specific OMC 7.4L configuration 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 #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;\"\u003eEngine oil + filter\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eUse marine‑grade oil; change more often for heavy loads or short‑run use\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\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;\"\u003eGear oil (drive)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect for water intrusion or metal; service seals if contamination is found\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\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 style=\"padding:8px;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect 100 hours; replace 200–300 hours\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eCheck gap and look for fouling or uneven color\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark plug\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eFuel filter \/ water separator\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eDrain water as needed; replace element regularly to protect injectors\/carb\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\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;\"\u003eWater pump impeller\/kit\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eEvery 1–2 seasons or 100–200 hours\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eCritical for cooling; replace sooner if stream is weak or overheat occurs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\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;\"\u003eAnodes (zinc\/aluminum\/magnesium)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect every 3 months; replace when \u0026gt;50% worn\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eChoose alloy for your water type (salt, brackish, fresh)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\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;\"\u003eAccessory\/serpentine belt\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect 100 hours; replace 300 hours or if cracked\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eProper tension prevents alternator and pump slip\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/belt\"\u003eBelt\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=\"padding:16px;\"\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\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\u003eCorrosion Protection — \u003ca href=\"https:\/\/seasierra.com\/collections\/bombardier-anodes\"\u003eJohnson\/Evinrude\/OMC Anodes\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase Seals — \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-lower-unit-seal-kits\"\u003eJohnson\/Evinrude\/OMC Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropellers — \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=\"padding:16px;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #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;\"\u003eWeak water stream or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eInspect intake screens, raw‑water impeller condition, and thermostat operation\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eWater pump impeller\/kit, thermostat, intake screen\/gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003ePoor acceleration or power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eCheck fuel quality, replace water‑separating filter, verify ignition timing and plug condition\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eFuel filter\/separator, spark plugs, ignition components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eHard starting or rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eTest battery and cables, inspect plugs and wires, check for vacuum leaks or contaminated fuel\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eSpark plugs, fuel filter, electrical items, gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;\"\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eDrain and inspect gear oil, check for water intrusion, pressure\/vacuum test seals\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;\"\u003eLower unit seal kit, bearings, gear oil\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=\"padding:16px;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable between Gen IV, Gen V, and Gen VI 7.4L engines?\u003c\/summary\u003e\n    \u003cp\u003eNot always. Cam\/lifters, gasket sets, and rear main seals differ by generation. Confirm your generation from serial\/model data and match parts accordingly.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should the raw‑water impeller be replaced?\u003c\/summary\u003e\n    \u003cp\u003eReplace every 1–2 seasons or 100–200 hours, and immediately if you see weak cooling flow, overheating, or impeller vane damage.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should gear oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eChange every 100 hours or annually. If water or metal is found, repair seals and re‑test before returning to 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 and drive serial\/model numbers, engine generation (IV\/V\/VI), rotation (LH\/RH), head style (oval\/rectangular port), and whether the raw‑water pump is in the drive or engine‑mounted.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"padding:16px; border-top:1px solid #e5e7eb;\"\u003e\n  \u003cp\u003eReady to find parts by model and year? Browse the main OMC collection and use Filter \u0026amp; Sort to narrow by category and fitment.\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;\"\u003eShop OMC Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px; color:#475569;\"\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-4-stroke-7-4l-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}