{"title":"MerCruiser 4-Stroke 185-500HP Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"max-width:1000px;margin:0 auto;padding:16px 12px;\"\u003e\n  \u003cp\u003eParts and service guidance for MerCruiser 4‑Stroke 185–500 HP sterndrive\/inboard engines. Use this page to find compatible maintenance items, commonly replaced components, and troubleshooting tips. You can also browse the main MerCruiser collection. Scroll to the bottom of this page to start browsing parts for your engine, and 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\/mercruiser\" style=\"display:inline-block;margin-top:8px;padding:10px 16px;background:#0b5cab;color:#fff;text-decoration:none;border-radius:4px;\"\u003eBrowse All MerCruiser Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"max-width:1000px;margin:0 auto;padding:12px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 185–500 HP MerCruiser Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate serial numbers: engine serial is typically on a decal near the flame arrestor or on the starboard side of the block; drive and transom assembly serials are on the sterndrive housing\/transom bracket (Alpha\/Bravo).\u003c\/li\u003e\n    \u003cli\u003eDecode the engine family: V6 4.3L, small‑block V8 (5.0\/5.7\/6.2), and big‑block V8 (8.2\/496\/502) each use different ignition, cooling, and exhaust parts. Always confirm by serial when ordering.\u003c\/li\u003e\n    \u003cli\u003eCheck suffix\/options: model codes and build sheets can indicate raw‑water vs closed‑cooling, carb\/TBI\/MPI\/EFI fuel systems, and drive type (Alpha vs Bravo) which affect pump, anode, and exhaust components.\u003c\/li\u003e\n    \u003cli\u003eMeasure shaft\/exhaust\/drive details if repowered: some boats may have been repowered; verify the current engine’s serial and the drive’s serial to ensure exact fit.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"max-width:1000px;margin:0 auto;padding:12px;\"\u003e\n  \u003ch2\u003ePlatform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003eV6 4.3L (Approx. 190–220 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 #ddd;padding:6px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e90° V6 4‑stroke, carb\/TBI\/MPI fuel systems; commonly paired with Alpha One Gen II drives.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e4.3L, 4.3LX, 4.3 MPI variants.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCompact, good fuel economy, easy service access in many engine bays.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eImpeller location depends on drive\/engine setup (Alpha in‑drive vs engine‑mounted sea pump). Verify by serial.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eSmall‑Block V8 5.0\/5.7\/6.2 (Approx. 220–350 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 #ddd;padding:6px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eV8 4‑stroke; carb\/TBI\/MPI\/EFI; used with Alpha and Bravo drives (Bravo often uses engine‑mounted raw‑water pumps).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e5.0L, 5.7L (350 MAG), 6.2L (MPI\/ECT).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eBroad torque curve, strong mid‑range, widely supported service parts.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eCooling, ignition, and exhaust components vary by generation; always match by engine serial and drive type.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eBig‑Block V8 8.2\/496\/502 (Approx. 375–500 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 #ddd;padding:6px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eLarge‑displacement V8 4‑stroke (EFI\/MPI), typically with Bravo One\/Bravo XR drives.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e496 MAG\/MAG HO, 8.2 MAG\/MAG HO, 502‑based performance packages.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eHigh output with robust cooling and exhaust hardware for sustained load.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eDifferent sea pumps, manifolds\/risers, and anodes than small‑blocks; confirm by serial and cooling type (raw vs closed).\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"service-kits\" style=\"max-width:1000px;margin:0 auto;padding:12px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines; always follow your MerCruiser service manual and the maintenance schedule specific to your engine serial and drive.\u003c\/p\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eEngine oil \u0026amp; filter\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eUse marine‑grade oil meeting MerCruiser spec; replace filter each service.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-oil-filters\"\u003eMerCruiser Oil Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eDrive gear lube (Alpha\/Bravo)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eDrain\/inspect for metal; replace seals if water intrusion is found.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-service-maintenance-kits\"\u003eMerCruiser Service \u0026amp; Maintenance Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e100 hrs or annually (inspect 50 hrs)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eReplace sooner if fouled or misfire occurs; gap per manual.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plug Collection\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eFuel filter \/ water separator\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eDrain\/replace to prevent lean conditions and stalling.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-fuel-filters\"\u003eMerCruiser Fuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eRaw‑water pump impeller\/kit\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e2 seasons or 200 hrs (inspect annually)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eBravo sea pump is engine‑mounted; Alpha typically uses in‑drive pump—verify configuration.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-impellers\"\u003eMerCruiser Impellers\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eAnodes (zinc\/aluminum\/magnesium)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInspect each haul‑out; replace when 50% consumed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eMatch material to water type (salt, brackish, fresh); include drive and transom assemblies.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-anodes\"\u003eMerCruiser Anodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;\"\u003eBellows (exhaust, u‑joint, shift)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eInspect annually; replace ~2–3 years\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eCracked bellows allow water ingress that can damage u‑joints and gimbal bearings.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/bellow\"\u003eBellows Collection\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"max-width:1000px;margin:0 auto;padding:12px;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service: \u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-service-maintenance-kits\"\u003eMerCruiser Service \u0026amp; Maintenance Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eOil \u0026amp; Filtration: \u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-oil-filters\"\u003eMerCruiser Oil Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System: \u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-impellers\"\u003eMerCruiser Impellers\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection: \u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-anodes\"\u003eMerCruiser Anodes\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eFuel System: \u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser-fuel-filters\"\u003eMerCruiser Fuel 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\u003eExhaust \u0026amp; Hardware: \u003ca href=\"https:\/\/seasierra.com\/collections\/manifolds\"\u003eManifolds\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"max-width:1000px;margin:0 auto;padding:12px;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eOverheat alarm or weak water flow\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eInspect sea strainer\/intake screens, raw‑water pump impeller, pump housing cover, and thermostat operation.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eWater pump impeller kit, pump cover, thermostat, intake screen, anodes.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003ePoor acceleration \/ power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eCheck fuel‑water separator, anti‑siphon valve, fuel pressure, ignition condition, and prop hub for slip.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eFuel filter, fuel pump, spark plugs, propeller\/hub kit.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eVerify battery voltage\/grounds, inspect IAC\/MAP (EFI), check vacuum leaks and plug condition.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;border-bottom:1px solid #eee;\"\u003eSpark plugs, filters, electrical connectors, sensors (as applicable).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px;\"\u003eGearcase noise or metal in gear lube\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eChange gear lube and examine magnetic plug; check u‑joints\/gimbal bearing; pressure test for seal leaks.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px;\"\u003eGear lube, seals, bellows, bearings.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"faq\" style=\"max-width:1000px;margin:0 auto;padding:12px;\"\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 carry across families, but many items (cooling, ignition, exhaust, sensors) changed between generations and between V6, small‑block V8, and big‑block V8 platforms. Always match by engine and drive serial numbers.\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 two seasons or 200 hours. Replace sooner if overheat or weak flow occurs, or if the impeller shows set or cracking.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should I change drive gear lube?\u003c\/summary\u003e\n    \u003cp\u003eTypically every 100 hours or annually. Drain and inspect for water or metal, and renew sealing washers. Pressure‑test the drive if contamination is found.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do I need to confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide the engine serial number, drive serial number (Alpha\/Bravo), cooling type (raw vs closed), and fuel system (carb\/TBI\/EFI\/MPI). Photos of the nameplate and the area of the part help speed verification.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"max-width:1000px;margin:0 auto;padding:16px 12px;border-top:1px solid #eee;\"\u003e\n  \u003cp\u003eReady to find the right parts? Browse the main MerCruiser collection and use Filter \u0026amp; Sort to narrow by horsepower, model year, and part group.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/mercruiser\" style=\"display:inline-block;margin:8px 0;padding:10px 16px;background:#0b5cab;color:#fff;text-decoration:none;border-radius:4px;\"\u003eShop MerCruiser Parts\u003c\/a\u003e\n  \u003cp style=\"font-size:0.95em;color:#444;\"\u003eIf you’re unsure about your model, send us a photo of the serial\/nameplate and the part you need—we’ll help verify compatibility.\u003c\/p\u003e\n\u003c\/section\u003e","products":[{"product_id":"thermostat-kit-140-f-60-c-fits-mercruiser-4-3l-5-0l-5-7l-7-4l-8-2l-replaces-807252q4-807252t4-807252t7","title":"140°F (60°C) Thermostat Kit for MerCruiser V6\/V8 Stern Drive Engines – Replaces 807252Q4, 807252T4, 807252T7, 8M0089715","description":"\u003csection\u003e\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;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003e140°F (60°C) thermostat kit\u003c\/strong\u003e is designed for MerCruiser V6 and V8 stern drive and outboard-drive cooling systems. It provides a complete thermostat-service solution with the thermostat, O-ring, and housing gaskets specified for the applicable assembly.\u003c\/p\u003e\n\u003cp\u003eThe thermostat is intended for systems that require a 140°F (60°C) opening temperature. Confirm the required temperature rating and the original part references for your exact engine before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e140°F (60°C) thermostat for applicable MerCruiser V6\/V8 cooling systems.\u003c\/li\u003e\n  \u003cli\u003eService kit includes the thermostat, O-ring, and multiple housing gaskets.\u003c\/li\u003e\n  \u003cli\u003eAftermarket replacement intended for direct replacement of the listed references.\u003c\/li\u003e\n  \u003cli\u003eFor stern drive and outboard-drive applications identified as MerCruiser V6\/V8.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number References\u003c\/h2\u003e\n\u003cp\u003eUse the following references to compare your original part and confirm compatibility. Reference numbers are provided for identification only; always verify the complete engine application.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number References\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n\u003cth\u003eReference Type\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\u003eMercury\/MerCruiser reference\u003c\/td\u003e\n\u003ctd\u003e807252Q4\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\/MerCruiser reference\u003c\/td\u003e\n\u003ctd\u003e807252T4\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\/MerCruiser reference\u003c\/td\u003e\n\u003ctd\u003e807252T7\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury\/MerCruiser reference\u003c\/td\u003e\n\u003ctd\u003e8M0089715\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eAftermarket\/catalog reference\u003c\/td\u003e\n\u003ctd\u003e18-3668\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eThis kit is listed for \u003cstrong\u003eMerCruiser V6 and V8 stern drive\/outboard-drive applications\u003c\/strong\u003e. Compatibility can vary by engine configuration, cooling-system arrangement, production year, and serial-number range. The available product record does not establish a universal year or serial-number range for every V6\/V8 engine.\u003c\/p\u003e\n\u003cp\u003eBefore installation, compare the thermostat temperature rating, housing gasket layout, and original part references with the contents listed below. Do not use this kit for a closed-cooling system unless the engine manufacturer specifies a 140°F thermostat for that system.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eThermostat service kit with O-ring and housing gaskets\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eMerCruiser stern drive\/outboard-drive V6 and V8 engines\u003c\/dd\u003e\n  \u003cdt\u003eThermostat Temperature\u003c\/dt\u003e\n  \u003cdd\u003e140°F (60°C)\u003c\/dd\u003e\n  \u003cdt\u003eThermostat Reference\u003c\/dt\u003e\n  \u003cdd\u003e59137\u003c\/dd\u003e\n  \u003cdt\u003eCooling-System Use\u003c\/dt\u003e\n  \u003cdd\u003eVerify the required thermostat rating and cooling-system configuration before installation\u003c\/dd\u003e\n  \u003cdt\u003eReplacement Type\u003c\/dt\u003e\n  \u003cdd\u003eAftermarket replacement\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1 x Thermostat, reference 59137\u003c\/li\u003e\n  \u003cli\u003e1 x O-ring, reference 25-30224\u003c\/li\u003e\n  \u003cli\u003e1 x Gasket, reference 27-33179-2\u003c\/li\u003e\n  \u003cli\u003e1 x Gasket, reference 27-47510\u003c\/li\u003e\n  \u003cli\u003e1 x Gasket, reference 27-41812\u003c\/li\u003e\n  \u003cli\u003e1 x Gasket, reference 27-48818-1\u003c\/li\u003e\n  \u003cli\u003e1 x Housing gasket, reference 27-33918\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eAllow the engine to cool completely before beginning work. Disconnect the battery and follow the engine manufacturer's safety procedures.\u003c\/li\u003e\n  \u003cli\u003eIdentify the thermostat housing and place a suitable drain pan beneath the service area.\u003c\/li\u003e\n  \u003cli\u003eRemove the housing fasteners and carefully separate the housing. Note the orientation of the original thermostat and gasket arrangement.\u003c\/li\u003e\n  \u003cli\u003eRemove the old thermostat, O-ring, and gasket material. Clean and inspect all mating surfaces without damaging the housing or engine components.\u003c\/li\u003e\n  \u003cli\u003eInstall the 140°F thermostat in the correct orientation and replace the O-ring and applicable housing gaskets from the kit.\u003c\/li\u003e\n  \u003cli\u003eReinstall the housing and tighten the fasteners to the engine manufacturer's specified torque.\u003c\/li\u003e\n  \u003cli\u003eRestore the cooling system using the correct procedure and fluid for the engine configuration. Check carefully for leaks.\u003c\/li\u003e\n  \u003cli\u003eRun the engine while monitoring the temperature and water flow. Stop immediately if the engine overheats or a leak appears.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I confirm that this kit is correct for my engine?\u003c\/summary\u003e\n  \u003cp\u003eConfirm that your engine is a MerCruiser V6 or V8 stern-drive\/outboard-drive application and that the original thermostat or service information references 140°F (60°C). Compare the original part references and gasket arrangement with the information on this page. If your engine has a closed-cooling system or a different temperature requirement, verify the specification with the engine manufacturer before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat does the kit include?\u003c\/summary\u003e\n  \u003cp\u003eThe kit includes one 140°F thermostat, one O-ring, and six listed gaskets for the thermostat housing and related housing surfaces. Tools, replacement fasteners, coolant, and sealants are not included.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are common symptoms of a failing thermostat?\u003c\/summary\u003e\n  \u003cp\u003eA thermostat that is stuck open may allow the engine to run cooler than specified, while a thermostat that is stuck closed can cause overheating. Restricted water flow, damaged gaskets, and other cooling-system faults can produce similar symptoms, so inspect the complete system before replacing parts.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM part?\u003c\/summary\u003e\n  \u003cp\u003eNo. This is an aftermarket replacement kit listed against the reference numbers shown on this page.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eCan I use this kit with any MerCruiser V6 or V8?\u003c\/summary\u003e\n  \u003cp\u003eNo universal fitment should be assumed. MerCruiser applications vary by model, cooling-system design, year, and serial number. Verify the original reference numbers, thermostat temperature, and gasket configuration before installation.\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 completely cool engine and follow the manufacturer's service procedures.\u003c\/li\u003e\n  \u003cli\u003eVerify the temperature rating, original part references, and gasket layout before purchase and installation.\u003c\/li\u003e\n  \u003cli\u003eDo not rely on engine displacement alone to confirm compatibility.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended when the correct housing configuration or cooling-system type is 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 Replacement Parts\u003c\/strong\u003e — We supply replacement components for marine service and repair applications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Listings\u003c\/strong\u003e — Product information is organized around reference numbers, operating specifications, and installation considerations.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eService-Ready Kits\u003c\/strong\u003e — This kit groups the thermostat, O-ring, and listed housing gaskets needed for the specified service application.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723789734203,"sku":"23TH635","price":33.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Thermostat_Kit_140_Degree_for_Mercruiser_43L_50L_57L_74L_82L_807252Q4_18-3668_______807252Q4_18-3668_-_JLM_MARINE-8291200.jpg?v=1763031830"}],"url":"https:\/\/seasierra.com\/collections\/mercruiser-4-stroke-185-500hp-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}