{"product_id":"sierra-18-3541-thermostat-for-yamaha-outboards-f6-f100-4-stroke-replaces-66m-12411-01-00","title":"Sierra 18-3541 Thermostat, 140F\/60C, Yamaha Outboard, Replaces 66M-12411-01-00","description":"\u003cp\u003eThe Sierra 18-3541 is a replacement cooling system thermostat engineered for Yamaha outboard engines. It regulates engine operating temperature by opening at a factory-calibrated 140 degrees F (60 degrees C), allowing coolant to circulate once the engine reaches proper operating temperature and helping prevent both overheating and prolonged cold-running operation. The thermostat is finished in white and is built to Sierra's quality standard, which the company states meets or exceeds the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003eThis is a direct-fit cooling system component intended for outboard owners performing routine maintenance or replacing a failed or stuck thermostat. Installing a properly rated thermostat is important for outboard longevity, since running without one or with an incorrect temperature rating can cause the engine to run too cool or too hot. The 18-3541 corresponds to the OEM Yamaha thermostat 66M-12411-01-00 used in Yamaha outboard cooling systems.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-3541\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Thermostat\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature Rating:\u003c\/strong\u003e 140 degrees F \/ 60 degrees C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 66M-12411-01-00\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Yamaha outboard engines\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for Yamaha outboard engine cooling systems using the 66M-12411-01-00 thermostat.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e66M-12411-01-00\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat temperature does the Sierra 18-3541 thermostat open at?\u003c\/strong\u003e It opens at 140 degrees F (60 degrees C), which is the calibrated rating for the Sierra 18-3541 thermostat.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the 18-3541 replace?\u003c\/strong\u003e The Sierra 18-3541 corresponds to Yamaha OEM thermostat 66M-12411-01-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3541 an OEM or aftermarket part?\u003c\/strong\u003e It is an aftermarket replacement thermostat that Sierra states meets or exceeds the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engines is the 18-3541 thermostat used on?\u003c\/strong\u003e The 18-3541 is used in Yamaha outboard engine cooling systems.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-3541 thermostat?\u003c\/strong\u003e It is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-3541 thermostat weigh?\u003c\/strong\u003e The Sierra 18-3541 thermostat weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-3541 come with a gasket?\u003c\/strong\u003e The Sierra 18-3541 listing covers the thermostat itself; check your engine's gasket part separately when ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if I install a thermostat with the wrong temperature rating?\u003c\/strong\u003e Using a thermostat rated differently than 140 degrees F (60 degrees C) can cause a Yamaha outboard to run too cool or too hot, so the 18-3541 should match this rating for proper cooling system operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Sierra 18-3541 covered under warranty?\u003c\/strong\u003e Yes, the Sierra 18-3541 thermostat is covered under Sierra's standard limited warranty.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if my thermostat needs replacing?\u003c\/strong\u003e Signs include an outboard engine that overheats, runs too cool, or shows inconsistent temperature gauge readings; a stuck or failed unit is commonly replaced with a direct-fit part like the Sierra 18-3541.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many thermostats are included with the 18-3541?\u003c\/strong\u003e The Sierra 18-3541 includes one thermostat.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988151349467,"sku":"SIE-18-3541","price":31.37,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-3541_lg__72200.1558126182.500.750.jpg?v=1785188316","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-3541-thermostat-for-yamaha-outboards-f6-f100-4-stroke-replaces-66m-12411-01-00","provider":"Good Vibes Marina","version":"1.0","type":"link"}