{"product_id":"emp-thermostat-120-degree-75-75517","title":"EMP Thermostat 120-Degree #75-75517","description":"\u003ch2\u003eEMP 75-75517 Thermostats \u0026amp; Parts\u003c\/h2\u003e\n\n\u003cp\u003eFour-stroke outboards run differently than two-strokes, and their cooling systems reflect that. Mercury and Mariner 4-stroke outboards in the 65 to 115 horsepower range are designed to operate at higher internal temperatures than their two-stroke counterparts, which is why the thermostat in these engines opens at 120 degrees Celsius (248 degrees Fahrenheit) rather than the lower ratings you will find on two-stroke applications. That higher operating temperature is intentional. It supports more complete combustion, better fuel efficiency, and lower emissions, all of which are part of what makes modern 4-stroke outboards as clean and efficient as they are. Using a thermostat with the wrong opening temperature on one of these engines will push it outside its designed operating range and undermine those advantages.\u003c\/p\u003e\n\n\u003cp\u003eThe EMP 75-75517 Thermostat fits Mercury and Mariner 4-stroke outboards across the 65, 75, 80, 90, 100, and 115 horsepower ratings. It is a direct replacement for Mercury and Mercruiser part number 8M0090819 and Sierra part number 18-3633. If you are cross-referencing from either of those numbers, you are in the right place. EMP manufactures this thermostat to OEM specifications, so the opening temperature, flow characteristics, and physical dimensions match the original exactly.\u003c\/p\u003e\n\n\u003cp\u003eThermostat replacement is a straightforward service item that is easy to include in a seasonal tune-up or any time the cooling system is opened for inspection. On a 4-stroke outboard that sees regular use, staying ahead of thermostat maintenance is a simple way to protect the engine and keep it running at the efficiency it was designed for.\u003c\/p\u003e\n\n\u003cp\u003eCompatibility and specs at a glance:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFits Mercury and Mariner 4-stroke outboards, 65, 75, 80, 90, 100, and 115 horsepower\u003c\/li\u003e\n  \u003cli\u003eOpens at 120 degrees Celsius (248 degrees Fahrenheit)\u003c\/li\u003e\n  \u003cli\u003eDesigned specifically for 4-stroke applications\u003c\/li\u003e\n  \u003cli\u003eReplaces Mercury and Mercruiser 8M0090819\u003c\/li\u003e\n  \u003cli\u003eReplaces Sierra 18-3633\u003c\/li\u003e\n  \u003cli\u003eBuilt to OEM specifications by EMP\u003c\/li\u003e\n  \u003cli\u003eDirect replacement, no modification required for listed applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cb\u003eNormalized SKU:\u003c\/b\u003e 7575517\u003cbr\u003e\u003cb\u003eUPC Code:\u003c\/b\u003e 840080496382\u003c\/p\u003e","brand":"EMP","offers":[{"title":"Default Title","offer_id":54081059094833,"sku":"EMP-75-75517","price":68.39,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0015\/7184\/8291\/files\/emp-thermostat-120-degree-75-75517-840080496382-1237373128.jpg?v=1778408874","url":"https:\/\/www.firstchoicemarine.com\/products\/emp-thermostat-120-degree-75-75517","provider":"First Choice Marine","version":"1.0","type":"link"}