{"product_id":"sierra-18-3540-marine-thermostat-50c-122f-for-yamaha-outboard-9-9-250-hp-replaces-oem-6e5-12411-30-00","title":"Sierra Thermostat 18-3540, Replaces Yamaha 6E5-12411-30-00, Fits T60 and T9.9 Outboards","description":"\u003cp\u003eThe Sierra 18-3540 is a replacement thermostat for Yamaha outboard engines, designed to regulate coolant flow so the engine reaches and holds its correct operating temperature. It opens at 122 degrees F (50 degrees C), matching the calibration of the original Yamaha thermostat it replaces. Sierra manufactures this part to meet or exceed the specification of the original equipment it is designed to replace, making it a straightforward drop-in swap during routine cooling system maintenance or when troubleshooting an overheating or slow-to-warm engine.\u003c\/p\u003e\u003cp\u003eThis thermostat is finished in white and is compatible with the Yamaha T60 and T9.9 outboard models noted below. Note that the 18-3540 will not fit the 31L engine. A gasket is not included with this thermostat and should be ordered separately to match your engine.\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 18-3540\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 122 degrees F \/ 50 degrees C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecial Feature:\u003c\/strong\u003e Adjustable\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282230975\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eYamaha T60 outboard (2003-06)\u003c\/li\u003e\n\u003cli\u003eYamaha T9.9 outboard (2005-06)\u003c\/li\u003e\n\u003cli\u003eWill not fit 31L engine\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e6E5-12411-30-00\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat temperature does the Sierra 18-3540 thermostat open at?\u003c\/strong\u003e The 18-3540 opens at 122 degrees F (50 degrees C), which matches the calibration of the Yamaha original equipment thermostat it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich Yamaha outboards fit the 18-3540 thermostat?\u003c\/strong\u003e The 18-3540 fits the Yamaha T60 outboard (2003-06) and the Yamaha T9.9 outboard (2005-06). It will not fit the 31L engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the 18-3540 replace?\u003c\/strong\u003e This thermostat replaces Yamaha OEM part number 6E5-12411-30-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs a gasket included with the 18-3540 thermostat?\u003c\/strong\u003e No, the Sierra 18-3540 is the thermostat only; a matching gasket is sold separately and should be selected to fit your specific engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-3540 thermostat?\u003c\/strong\u003e The 18-3540 has a white finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-3540 thermostat weigh?\u003c\/strong\u003e The 18-3540 thermostat weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3540 a genuine Yamaha part or an aftermarket replacement?\u003c\/strong\u003e The 18-3540 is a Sierra-manufactured replacement thermostat engineered to meet or exceed the specification of the original Yamaha equipment it replaces, identified by OEM number 6E5-12411-30-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the 18-3540 fit a 31L Yamaha engine?\u003c\/strong\u003e No, the 18-3540 thermostat will not fit the 31L engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat symptoms indicate I need to replace this thermostat?\u003c\/strong\u003e An engine that overheats, runs cold, or warms up slowly can indicate a failed thermostat; the 18-3540 is designed to restore proper coolant regulation on covered Yamaha T60 and T9.9 outboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-3540 thermostat?\u003c\/strong\u003e The UPC for the Sierra 18-3540 thermostat is 808282230975.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988151152859,"sku":"SIE-18-3540","price":21.67,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-3540_lg__24601.1558126118.500.750.jpg?v=1785188050","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-3540-marine-thermostat-50c-122f-for-yamaha-outboard-9-9-250-hp-replaces-oem-6e5-12411-30-00","provider":"Good Vibes Marina","version":"1.0","type":"link"}