{"product_id":"thermostat-60-c-140-f-fits-mercury-mariner-75-225-hp-replaces-8m0175321-855676004-8m6010296","title":"Thermostat (60°C\/140°F) – Fits Mercury\/Mariner 75-225 HP (Replaces 8M0175321, 855676004, 8M6010296)","description":"\u003cstyle\u003e\n  \/* Outer container allows horizontal scrolling (with iOS momentum) *\/\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n\n  \/* Base table styles *\/\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\n  \/* Key: prevent wrapping, word breaks, and vertical text in headers *\/\n  table.ss-table th {\n    white-space:nowrap;       \/* Do not wrap *\/\n    word-break:normal;        \/* Don’t break words *\/\n    letter-spacing:normal;    \/* Prevent theme styles from stretching letters *\/\n    font-weight:600;\n    background:#f8fafc;\n  }\n\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 \u003cstrong\u003eThermostat (60°C\/140°F) – Fits Mercury\/Mariner 75-225 HP Outboard Engines (Replaces 8M0175321, 855676004, 8M6010296)\u003c\/strong\u003e is a crucial component for maintaining optimal engine temperature in Mercury and Mariner outboard engines. It is designed for a precise fit on 75 HP, 80 HP, 90 HP, 100 HP, and 225 HP 4-stroke models across various serial number ranges.\u003c\/p\u003e\n    \u003cp\u003eIt serves as a direct interchange for Mercury part numbers 855676004, 8M0175321, 8M6010296, and 8556761, as well as Sierra 18-3632.\u003c\/p\u003e\n    \u003cul\u003e\n        \u003cli\u003eEngineered for direct OEM-replacement fit and function.\u003c\/li\u003e\n        \u003cli\u003eRegulates engine temperature at a 60°C (140°F) opening threshold.\u003c\/li\u003e\n        \u003cli\u003eSpecifically designed for use in closed cooling systems on outboard marine engines.\u003c\/li\u003e\n    \u003c\/ul\u003e\n\n    \u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n    \u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket.\u003c\/p\u003e\n    \u003cdiv class=\"ss-table-wrap\"\u003e\n        \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n            \u003cthead\u003e\n                \u003ctr\u003e\n                    \u003cth\u003eBrand\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\u003c\/td\u003e\n                    \u003ctd\u003e855676004\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003e8M0175321\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003e8M6010296\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003e8556761\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eSierra\u003c\/td\u003e\n                    \u003ctd\u003e18-3632\u003c\/td\u003e\n                \u003c\/tr\u003e\n            \u003c\/tbody\u003e\n        \u003c\/table\u003e\n    \u003c\/div\u003e\n\n    \u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n    \u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n    \u003cp\u003eThis thermostat is compatible with a range of 4-stroke outboard models from Mercury and Mariner, including specific CARB and EFI versions based on serial number.\u003c\/p\u003e\n    \u003cdiv class=\"ss-table-wrap\"\u003e\n        \u003ctable class=\"ss-table\" aria-label=\"Engine \u0026amp; Model Compatibility\"\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\u003eStroke\u003c\/th\u003e\n                    \u003cth\u003eOEM Part No.\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\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e75\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eCARB models (Serial 0G960500 through 1B226999)\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e75\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eEFI models (Serial 0G1B172291 through 1B366822)\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e80\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eEFI models (Serial 1B227000 through 1B366822)\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e90\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eCARB models (Serial 0G960500 \u0026amp; Up)\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e90\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eEFI models (Serial 1B172291 through 1B366822)\u003c\/td\u003e\n                 \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e100\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eEFI models (Serial 1B227000 through 1B366822)\u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003eMercury\u003c\/td\u003e\n                    \u003ctd\u003eOutboard\u003c\/td\u003e\n                    \u003ctd\u003e225\u003c\/td\u003e\n                    \u003ctd\u003e4-Stroke\u003c\/td\u003e\n                    \u003ctd\u003e855676004\/8M0175321\/8M6010296\u003c\/td\u003e\n                    \u003ctd\u003eEFI models (Serial 0T653945 \u0026amp; Up)\u003c\/td\u003e\n                \u003c\/tr\u003e\n            \u003c\/tbody\u003e\n        \u003c\/table\u003e\n    \u003c\/div\u003e\n\n    \u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n    \u003cdl\u003e\n        \u003cdt\u003eProduct Type\u003c\/dt\u003e\n\u003cdd\u003eMarine Engine Thermostat\u003c\/dd\u003e\n        \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect OEM replacement\u003c\/dd\u003e\n        \u003cdt\u003eTemperature Rating\u003c\/dt\u003e\n\u003cdd\u003e60°C (140°F)\u003c\/dd\u003e\n        \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eBrass\/Stainless Steel\u003c\/dd\u003e\n        \u003cdt\u003eOperating Temperature\u003c\/dt\u003e\n\u003cdd\u003e60°C (140°F) opening temperature\u003c\/dd\u003e\n        \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eDesigned for closed cooling systems in outboard marine engines\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 60°C (140°F) Thermostat (855676004\/8M0175321\/8M6010296)\u003c\/li\u003e\n    \u003c\/ul\u003e\n\n    \u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n    \u003col\u003e\n        \u003cli\u003eEnsure the engine has cooled down completely before beginning work.\u003c\/li\u003e\n        \u003cli\u003eDrain the engine coolant to a level below the thermostat housing.\u003c\/li\u003e\n        \u003cli\u003eCarefully remove the bolts securing the thermostat housing cover.\u003c\/li\u003e\n        \u003cli\u003eNote the orientation of the old thermostat before lifting it out.\u003c\/li\u003e\n        \u003cli\u003eRemove the old thermostat and any existing gasket or seal material. Thoroughly clean the mating surfaces of the housing and cover.\u003c\/li\u003e\n        \u003cli\u003eInstall the new thermostat in the correct orientation.\u003c\/li\u003e\n        \u003cli\u003ePlace the new gasket or seal (not included with this part) and reinstall the housing cover, tightening bolts to the manufacturer's specifications.\u003c\/li\u003e\n        \u003cli\u003eRefill the cooling system with the correct type and amount of coolant.\u003c\/li\u003e\n        \u003cli\u003eStart the engine, check for any leaks, and monitor the temperature gauge to confirm the thermostat opens at the correct temperature.\u003c\/li\u003e\n    \u003c\/ol\u003e\n\n    \u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eHow do I know if my thermostat is failing?\u003c\/summary\u003e\n        \u003cp\u003eCommon signs of a faulty thermostat include engine overheating (stuck closed) or taking too long to reach operating temperature (stuck open). You may see alarms on your dash, erratic temperature gauge readings, or notice increased fuel consumption.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eWhy is the 60°C (140°F) temperature rating important?\u003c\/summary\u003e\n        \u003cp\u003eThis rating ensures the engine warms up quickly but doesn't overheat. It's the temperature at which the thermostat begins to open, allowing coolant to circulate through the engine. Using the wrong temperature can lead to poor performance, carbon buildup, or engine damage.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eCan I test my old thermostat?\u003c\/summary\u003e\n        \u003cp\u003eYes. Suspend the thermostat in a pot of water with a thermometer. Heat the water and observe the temperature at which the thermostat begins to open. If it doesn't open at or near its 60°C (140°F) rating, or if it doesn't open at all, it should be replaced.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eIs a gasket or seal included with this thermostat?\u003c\/summary\u003e\n        \u003cp\u003eThis listing is for the thermostat only. Gaskets and seals are sold separately. It is critical to use new gaskets\/seals during installation to prevent coolant leaks.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eHow often should a marine thermostat be replaced?\u003c\/summary\u003e\n        \u003cp\u003eThermostats don't have a fixed replacement interval, but it's good practice to inspect them during regular cooling system service (every 1-2 years for saltwater use) and replace them if there are any signs of corrosion or if engine temperature issues arise.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eOEM vs. Aftermarket?\u003c\/summary\u003e\n        \u003cp\u003eThis listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eShipping speed \u0026amp; cost\u003c\/summary\u003e\n        \u003cp\u003eWe ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eWarranty \u0026amp; returns\u003c\/summary\u003e\n        \u003cp\u003eCovered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused \u0026amp; in original condition). See our policy page or reach out for instructions.\u003c\/p\u003e\n    \u003c\/details\u003e\n\n    \u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n    \u003cul\u003e\n        \u003cli\u003eVerify images\/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.\u003c\/li\u003e\n        \u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n        \u003cli\u003eProfessional installation is recommended for safety and performance.\u003c\/li\u003e\n    \u003c\/ul\u003e\n\n    \u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n    \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003ePro-Grade Standards\u003c\/strong\u003e — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — Fair pricing without compromising on materials or QC.\u003c\/li\u003e\n    \u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723983130939,"sku":"23TH626","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Thermostat_for_Mercury_Outboard_75HP_90HP_100HP_225HP_855676004_8M0175321_8M6010296___855676004_8M0175321_-_JLM_MARINE-8291302.jpg?v=1763039355","url":"https:\/\/seasierra.com\/products\/thermostat-60-c-140-f-fits-mercury-mariner-75-225-hp-replaces-8m0175321-855676004-8m6010296","provider":"SeaSierra","version":"1.0","type":"link"}