{"product_id":"f-s-p-thermostat-kit-for-mercury-mariner-3-cylinder-40-60-hp-direct-fit-oem-replacement","title":"F.S.P Thermostat Kit for Mercury Mariner 3-Cylinder 40–60 HP — Direct-Fit OEM Replacement","description":"\u003cp\u003e\u003cstrong\u003eF.S.P's thermostat kit is a direct replacement thermostat assembly designed to restore proper engine cooling for Mercury Mariner 3-cylinder 2-stroke outboards (40–60 HP) using part numbers 59078A2, 13141, and 850055A2.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis replacement kit fits a range of Mercury Mariner GLM 110 3-cylinder 2-stroke engines (40, 50, 55, 60 HP) and is engineered to match OEM fit and function. It’s supplied as a single, complete thermostat kit and cross-references common Mercury part numbers so you can replace the failing thermostat quickly and avoid overheating or inefficient engine warm-up caused by a faulty unit.\u003c\/p\u003e\n\n\u003ch3\u003eWhich Mercury engines and serial ranges does this thermostat kit fit?\u003c\/h3\u003e\n\u003cp\u003eThis F.S.P kit is specifically listed for 3-cylinder 2-stroke Mercury Mariner engines in the 40–60 HP range. Fitment varies by horsepower and origin (USA\/BEL) and is set by serial number ranges to ensure compatibility.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e40 HP: USA serial 0G531301 \u0026amp; up, BEL 9973100 \u0026amp; up\u003c\/li\u003e\n  \u003cli\u003e50, 55, 60 HP: USA serial 0G590000 \u0026amp; up, BEL 9973100 \u0026amp; up\u003c\/li\u003e\n  \u003cli\u003eCross-replaces Mercury part numbers 850055A2, 850055A1, 59078A2, 13141\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat does the kit include and how does it replace the original part?\u003c\/h3\u003e\n\u003cp\u003eThe package contains one complete thermostat kit designed to replace the listed Mercury part numbers. The components are sized and shaped to install in the factory thermostat housing without modification, restoring correct coolant flow control.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOne thermostat kit per box, ready for installation\u003c\/li\u003e\n  \u003cli\u003eDirect-fit components matched to OEM dimensions and seals\u003c\/li\u003e\n  \u003cli\u003eNo additional gaskets or machining typically required\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow will installing this thermostat kit affect engine performance?\u003c\/h3\u003e\n\u003cp\u003eA correctly operating thermostat helps the engine reach and maintain optimal operating temperature faster and keeps temperature steady under load. Replacing a sticking or failed thermostat can reduce warm-up time and prevent overheating, improving fuel efficiency and protecting engine components.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHelps maintain steady coolant temperature during operation\u003c\/li\u003e\n  \u003cli\u003eReduces risk of overheating from a stuck-closed thermostat\u003c\/li\u003e\n  \u003cli\u003eSupports proper thermally controlled engine timing and performance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow difficult is installation and what should I check before buying?\u003c\/h3\u003e\n\u003cp\u003eInstallation is typically straightforward for anyone comfortable with basic outboard service; it requires access to the thermostat housing and simple hand tools. Before purchasing, verify your engine model and serial number against the listed fitment to ensure compatibility and inspect the housing for corrosion that might require additional parts.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eBasic mechanic skills and standard tools usually sufficient\u003c\/li\u003e\n  \u003cli\u003eConfirm engine model and serial number match fitment ranges\u003c\/li\u003e\n  \u003cli\u003eInspect thermostat housing and surrounding seals for wear\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This F.S.P thermostat kit is intended for boat owners, marine mechanics, and service shops maintaining Mercury Mariner GLM 110 3-cylinder 2-stroke outboards (40–60 HP) who need a reliable, direct-fit replacement for failing or worn thermostats. Choose this kit when your engine shows warming issues, fluctuating temperatures, or if you’re performing routine cooling-system maintenance and want an OEM-compatible replacement part.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this kit replace Mercury part 850055A2?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. This F.S.P kit cross-references and replaces Mercury part numbers including 850055A2, 850055A1, 59078A2, and 13141.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I install this kit myself?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, with basic mechanical skills and standard tools most owners can replace the thermostat; verify engine serial number for fitment first.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"F.S.P","offers":[{"title":"Default Title","offer_id":48086717071518,"sku":"B09YTJNQ1J","price":58.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/fsp-thermostat-kit-front-view.jpg?v=1785902874","url":"https:\/\/northtrailauto.ca\/products\/f-s-p-thermostat-kit-for-mercury-mariner-3-cylinder-40-60-hp-direct-fit-oem-replacement","provider":"North Trail Auto","version":"1.0","type":"link"}