{"product_id":"stainless-steel-marine-thermostat-18-3543-for-johnson-evinrude-200-235-hp-outboards-1977-1985","title":"EMP Stainless Steel Thermostat 75-00403, Replaces 18-3543, Johnson\/Evinrude Outboards","description":"\u003cp\u003eThe EMP 75-00403 is a stainless steel thermostat engineered as a direct replacement for Johnson\/Evinrude outboard engines. Stainless steel construction resists the corrosion and mineral buildup common in raw-water cooling systems, helping the thermostat maintain accurate opening temperature over repeated heat cycles. Correct thermostat function is critical to outboard engine health: it regulates coolant flow so the engine reaches and holds proper operating temperature, protecting against both overheating and the inefficient combustion that comes from running too cold. This thermostat is a straightforward maintenance-item replacement for engines showing symptoms of a failed or sticking thermostat, such as overheating alarms, erratic temperature gauge readings, or reduced performance. It cross-references directly to OEM part number 18-3543, making it easy to confirm fit against your existing part before ordering. The EMP 75-00403 is intended for outboard engines in the Johnson\/Evinrude (OMC\/BRP) lineup, including 200 HP (1977-83) and 235 HP (1978-85) applications. Keeping a spare on hand is good practice for seasonal maintenance or as an emergency replacement, since a failed thermostat can leave an engine unable to run safely at operating temperature.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e EMP\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 75-00403\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Thermostat (Stainless Steel)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.061 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 840080461175\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e 18-3543\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eJohnson\/Evinrude (OMC\/BRP) outboard, 200 HP, 1977-83\u003c\/li\u003e\n\u003cli\u003eJohnson\/Evinrude (OMC\/BRP) outboard, 235 HP, 1978-85\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e18-3543\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the EMP 75-00403 thermostat replace?\u003c\/strong\u003e The EMP 75-00403 is a direct cross-reference for OEM part number 18-3543, so it installs as a like-for-like replacement without needing to modify the cooling system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does this thermostat fit?\u003c\/strong\u003e This thermostat fits Johnson\/Evinrude (OMC\/BRP) outboard engines, specifically 200 HP models from 1977-83 and 235 HP models from 1978-85.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 75-00403 thermostat made from?\u003c\/strong\u003e It is made from stainless steel, chosen for its resistance to corrosion and mineral scale buildup in raw-water cooling systems.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the EMP 75-00403 thermostat weigh?\u003c\/strong\u003e The thermostat weighs 0.061 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this an OEM or aftermarket thermostat?\u003c\/strong\u003e The EMP 75-00403 is an aftermarket thermostat manufactured to match the specifications and function of OEM part 18-3543.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are signs my outboard thermostat needs to be replaced?\u003c\/strong\u003e Common symptoms include the engine overheating, an erratic or fluctuating temperature gauge, or the engine running noticeably cooler than normal, all of which point to a stuck or failed thermostat like the one the 75-00403 replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 75-00403 include a gasket?\u003c\/strong\u003e The dossier for the EMP 75-00403 does not list a gasket as part of this item, so buyers should check their existing gasket condition separately.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the 75-00403 thermostat on a different HP outboard than listed?\u003c\/strong\u003e Fitment for the EMP 75-00403 is confirmed for Johnson\/Evinrude 200 HP (1977-83) and 235 HP (1978-85) outboards; applications outside those are not confirmed by the available specifications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the EMP 75-00403 thermostat?\u003c\/strong\u003e The UPC for this thermostat is 840080461175.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy does thermostat material matter on a marine engine?\u003c\/strong\u003e Stainless steel construction, as used in the EMP 75-00403, resists the corrosion that raw-water cooling systems cause in lower-grade metals, helping the thermostat hold its calibrated opening temperature longer.\u003c\/p\u003e","brand":"EMP","offers":[{"title":"Default Title","offer_id":48991291670747,"sku":"EMP-75-00403","price":19.2,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/EMP_75-00403_BRP_Thermostat_Kit__11349.1722489639.500.750.jpg?v=1785329112","url":"https:\/\/www.goodvibesmarina.com\/products\/stainless-steel-marine-thermostat-18-3543-for-johnson-evinrude-200-235-hp-outboards-1977-1985","provider":"Good Vibes Marina","version":"1.0","type":"link"}