{"product_id":"18-3653-thermostat-kit-for-omc-volvo-penta-mercruiser","title":"18-3653 Thermostat Kit for OMC Volvo Penta Mercruiser | JLM Marine","description":"\u003ch2\u003e18-3653 Thermostat Kit for OMC Volvo Penta Mercruiser | JLM Marine\u003c\/h2\u003e\n\n\u003cp\u003eThis \u003cstrong\u003e160°F thermostat kit\u003c\/strong\u003e is engineered for OMC Sterndrive\/Cobra applications and is compatible with \u003cstrong\u003eVolvo Penta\u003c\/strong\u003e and \u003cstrong\u003eMercruiser\u003c\/strong\u003e engines spanning from 1969 to 1988. It provides reliable temperature regulation across a wide range of horsepower ratings—from 90 HP to 454 HP—and displacement sizes including 3.8L, 4.3L, 5.0L, 5.7L, and 7.5L models.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDirect Replacement for:\u003c\/strong\u003e Mercruiser 802259, 802326 | OMC 379754, 383307, 3852216, 3856961, 778056 | Volvo Penta 3852127, 3852216, 3856961 | GLM 13430 | Sierra 18-3653, 18-3554, 18-3677.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eComplete kit with thermostat, O-ring, gaskets, and housing gasket for fast installation\u003c\/li\u003e\n\u003cli\u003eRated at \u003cstrong\u003e160°F\u003c\/strong\u003e for optimal cooling performance in marine inboard\/sterndrive applications\u003c\/li\u003e\n\u003cli\u003eFits dozens of OMC engine models from 1969–1988, covering popular displacement classes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Cross-Reference\u003c\/h2\u003e\n\u003cp\u003eUse this table to confirm equivalent part numbers across OEM and aftermarket brands.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable border=\"1\" cellpadding=\"6\" cellspacing=\"0\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\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\u003eMERCRUISER\u003c\/td\u003e\n\u003ctd\u003e802259\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMERCRUISER\u003c\/td\u003e\n\u003ctd\u003e802326\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC\u003c\/td\u003e\n\u003ctd\u003e379754\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC\u003c\/td\u003e\n\u003ctd\u003e383307\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC\u003c\/td\u003e\n\u003ctd\u003e3852216\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC\u003c\/td\u003e\n\u003ctd\u003e3856961\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC\u003c\/td\u003e\n\u003ctd\u003e778056\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVOLVO PENTA\u003c\/td\u003e\n\u003ctd\u003e3852127\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVOLVO PENTA\u003c\/td\u003e\n\u003ctd\u003e3852216\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVOLVO PENTA\u003c\/td\u003e\n\u003ctd\u003e3856961\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGLM\u003c\/td\u003e\n\u003ctd\u003e13430\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3653\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3554\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3677\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eCompatible Engine Models\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable border=\"1\" cellpadding=\"6\" cellspacing=\"0\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eYears\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e90\u003c\/td\u003e\n\u003ctd\u003e90\u003c\/td\u003e\n\u003ctd\u003e1970\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e1972-73\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e120\u003c\/td\u003e\n\u003ctd\u003e120\u003c\/td\u003e\n\u003ctd\u003e1969-80\u003c\/td\u003e\n\u003ctd\u003e1980 models with \"C\" suffix only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e140\u003c\/td\u003e\n\u003ctd\u003e140\u003c\/td\u003e\n\u003ctd\u003e1973-80\u003c\/td\u003e\n\u003ctd\u003e1980 models with \"C\" suffix only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e155\u003c\/td\u003e\n\u003ctd\u003e155\u003c\/td\u003e\n\u003ctd\u003e1969-72\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e165\u003c\/td\u003e\n\u003ctd\u003e165\u003c\/td\u003e\n\u003ctd\u003e1972-76\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e170\u003c\/td\u003e\n\u003ctd\u003e170\u003c\/td\u003e\n\u003ctd\u003e1974\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e175\u003c\/td\u003e\n\u003ctd\u003e175\u003c\/td\u003e\n\u003ctd\u003e1975-77\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e185\u003c\/td\u003e\n\u003ctd\u003e185\u003c\/td\u003e\n\u003ctd\u003e1978-80\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e190\u003c\/td\u003e\n\u003ctd\u003e190\u003c\/td\u003e\n\u003ctd\u003e1974-77\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e200\u003c\/td\u003e\n\u003ctd\u003e200\u003c\/td\u003e\n\u003ctd\u003e1979-81\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e210\u003c\/td\u003e\n\u003ctd\u003e210\u003c\/td\u003e\n\u003ctd\u003e1969-72\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e215\u003c\/td\u003e\n\u003ctd\u003e215\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e225\u003c\/td\u003e\n\u003ctd\u003e225\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e230\u003c\/td\u003e\n\u003ctd\u003e230\u003c\/td\u003e\n\u003ctd\u003e1979-81\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e235\u003c\/td\u003e\n\u003ctd\u003e235\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e235\u003c\/td\u003e\n\u003ctd\u003e235\u003c\/td\u003e\n\u003ctd\u003e1975-77\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e240\u003c\/td\u003e\n\u003ctd\u003e240\u003c\/td\u003e\n\u003ctd\u003e1978\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e245\u003c\/td\u003e\n\u003ctd\u003e245\u003c\/td\u003e\n\u003ctd\u003e1972-75\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e250\u003c\/td\u003e\n\u003ctd\u003e250\u003c\/td\u003e\n\u003ctd\u003e1970-73 \u0026amp; 1979\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e260\u003c\/td\u003e\n\u003ctd\u003e260\u003c\/td\u003e\n\u003ctd\u003e1979-81\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e305\u003c\/td\u003e\n\u003ctd\u003e305\u003c\/td\u003e\n\u003ctd\u003e1977-82\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e350\u003c\/td\u003e\n\u003ctd\u003e350\u003c\/td\u003e\n\u003ctd\u003e1977-82\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e454\u003c\/td\u003e\n\u003ctd\u003e454\u003c\/td\u003e\n\u003ctd\u003e1977-82\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e3.8L\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003ctd\u003e1981-85\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e4.3L\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003ctd\u003e1985-86\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e5.0L\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003ctd\u003e1982-88\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e5.7L\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003ctd\u003e1982-88\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra\u003c\/td\u003e\n\u003ctd\u003e7.5L\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003ctd\u003e1988\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable border=\"1\" cellpadding=\"6\" cellspacing=\"0\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermostat Temperature Rating\u003c\/td\u003e\n\u003ctd\u003e160°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOEM Number\u003c\/td\u003e\n\u003ctd\u003e18-3653\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eOMC Sterndrive\/Cobra I\/O\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\u003cp\u003eThis complete thermostat kit includes everything you need for a straightforward installation:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e1 × Thermostat (160°F)\u003c\/li\u003e\n\u003cli\u003e1 × O-ring\u003c\/li\u003e\n\u003cli\u003e1 × Gasket\u003c\/li\u003e\n\u003cli\u003e1 × Gasket (additional)\u003c\/li\u003e\n\u003cli\u003e1 × Housing Gasket\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eAllow the engine to cool completely before beginning work. Relieve cooling system pressure by slowly opening the pressure cap.\u003c\/li\u003e\n\u003cli\u003eLocate the thermostat housing on your engine block and disconnect any hoses or electrical sensors as needed.\u003c\/li\u003e\n\u003cli\u003eRemove the housing bolts and carefully lift the housing away. Take note of the old thermostat's orientation.\u003c\/li\u003e\n\u003cli\u003eClean all gasket surfaces thoroughly using a gasket scraper and suitable solvent; ensure no old gasket material remains.\u003c\/li\u003e\n\u003cli\u003eInstall the new O-ring onto the thermostat body, then position the thermostat in the housing with the correct orientation (spring side typically down).\u003c\/li\u003e\n\u003cli\u003ePlace the new gasket(s) onto the mating surfaces and position the housing back onto the engine block.\u003c\/li\u003e\n\u003cli\u003eReinstall and torque the housing bolts to manufacturer specifications in a crisscross pattern.\u003c\/li\u003e\n\u003cli\u003eReconnect hoses and sensors, then refill the cooling system with the recommended coolant mixture.\u003c\/li\u003e\n\u003cli\u003eStart the engine and allow it to reach normal operating temperature while checking for leaks around the thermostat housing.\u003c\/li\u003e\n\u003cli\u003eTop off coolant as necessary and re-check the system after a short test run.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How do I confirm this thermostat kit fits my OMC, Volvo Penta, or Mercruiser engine?\u003c\/strong\u003e\u003cbr\u003e\nA: Cross-reference your engine's model, horsepower, and year with the compatibility table above. Also verify your existing thermostat's OEM part number against the cross-reference list to ensure a match.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What are the signs that my thermostat needs replacement?\u003c\/strong\u003e\u003cbr\u003e\nA: Common symptoms include engine overheating, failure to reach normal operating temperature, erratic temperature gauge readings, or coolant leaks around the thermostat housing. If you notice any of these issues, inspect and replace the thermostat as needed.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How often should I replace my marine thermostat?\u003c\/strong\u003e\u003cbr\u003e\nA: Most marine thermostats should be inspected annually and replaced every 2–3 years or per your engine manufacturer's maintenance schedule. Replace sooner if you experience overheating or cooling system issues.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Does this kit include all necessary gaskets and seals?\u003c\/strong\u003e\u003cbr\u003e\nA: Yes, this kit includes the thermostat, O-ring, multiple gaskets, and a housing gasket—everything required for a complete installation without additional parts.\u003c\/p\u003e\n\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVerify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.\u003c\/li\u003e\n\u003cli\u003eThis product is an aftermarket replacement part and is not an OEM component.\u003c\/li\u003e\n\u003cli\u003eProfessional installation is recommended to ensure safety and optimal performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy Choose JLM MARINE?\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality Assured:\u003c\/strong\u003e As a trusted manufacturer for over 20 years, we supply top marine brands globally.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast Global Shipping:\u003c\/strong\u003e Free delivery worldwide in 5–15 days.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect from Manufacturer:\u003c\/strong\u003e Competitive pricing without compromising quality.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"JLM Marine","offers":[{"title":"Default Title","offer_id":50603427266873,"sku":"23TH618","price":15.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0885\/0433\/6697\/files\/23TH618_1_45ac0051-3ad4-43cb-b1d2-349e2bf7ac4c.jpg?v=1755251462","url":"https:\/\/jlmmarine.com\/products\/18-3653-thermostat-kit-for-omc-volvo-penta-mercruiser","provider":"JLM Marine Boat Parts Limited","version":"1.0","type":"link"}