{"product_id":"thermostat-diaphragm-gasket-for-evinrude-johnson-v-4-v-6-loop-charge-replaces-omc-394408-sierra-18-1222","title":"Sierra 18-1222 Thermostat Diaphragm Gasket, Johnson\/Evinrude V4\/V6 200\/225 HP 1988-93, Replaces OMC 394408","description":"\u003cp\u003eThe Sierra 18-1222 is a round thermostat diaphragm gasket for Johnson\/Evinrude V4\/V6 loop charge outboard engines. It seals the thermostat housing to the powerhead, maintaining proper cooling system pressure and preventing water leakage around the thermostat. This gasket is manufactured to meet or exceed original equipment specifications, making it a direct equivalent for the OEM diaphragm gasket used on covered Johnson\/Evinrude V4\/V6 outboards.\u003c\/p\u003e\u003cp\u003eThe gasket is a round, white component sized to match the OEM thermostat housing footprint on applicable Johnson\/Evinrude V4\/V6 powerheads. It is commonly replaced whenever the thermostat itself is serviced, since a worn or hardened gasket is a frequent source of coolant leaks and overheating on outboard motors. Fitment covers 200 HP and 225 HP Johnson\/Evinrude outboards for the 1988-93 model years.\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 18-1222\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Thermostat Diaphragm Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\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 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999752376\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e GLM 46130, 394408\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eJohnson\/Evinrude V4\/V6 loop charge outboard, 200 HP, 1988-93\u003c\/li\u003e\n\u003cli\u003eJohnson\/Evinrude V4\/V6 loop charge outboard, 225 HP, 1988-93\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 46130\u003c\/li\u003e\n\u003cli\u003e394408\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-1222 thermostat diaphragm gasket fit?\u003c\/strong\u003e The Sierra 18-1222 fits Johnson\/Evinrude V4\/V6 loop charge outboard engines rated at 200 HP and 225 HP for the 1988-93 model years.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-1222 a direct OEM equivalent?\u003c\/strong\u003e Yes, the 18-1222 is interchangeable with GLM 46130 and OEM number 394408, and it meets or exceeds the quality of the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does 18-1222 cross-reference to?\u003c\/strong\u003e 18-1222 crosses to GLM 46130 and OMC\/Evinrude\/Johnson 394408.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape and color is this gasket?\u003c\/strong\u003e The 18-1222 thermostat diaphragm gasket is round and white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-1222 gasket weigh?\u003c\/strong\u003e It weighs 0.01 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShould the thermostat diaphragm gasket be replaced when installing a new thermostat?\u003c\/strong\u003e Yes, replacing the 18-1222 gasket whenever the thermostat is serviced helps prevent coolant leaks caused by a worn or hardened seal at the thermostat housing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included with the Sierra 18-1222?\u003c\/strong\u003e The 18-1222 is sold as a single thermostat diaphragm gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-1222 genuine Sierra or aftermarket?\u003c\/strong\u003e It is a genuine Sierra-branded part manufactured to meet or exceed the OEM specification for part 394408, not a generic aftermarket substitute.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-1222 gasket?\u003c\/strong\u003e The UPC is 030999752376.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-1222 gasket work on 235 HP or 200 HP 1977-83 Johnson\/Evinrude engines?\u003c\/strong\u003e No, the 18-1222 is specified for 200 HP and 225 HP Johnson\/Evinrude V4\/V6 outboards built 1988-93; earlier 200 HP (1977-83) and 235 HP applications use a different Sierra thermostat gasket.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988087058651,"sku":"SIE-18-1222","price":14.38,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-1222_lg__91690.1558121932.500.750.jpg?v=1785188297","url":"https:\/\/www.goodvibesmarina.com\/products\/thermostat-diaphragm-gasket-for-evinrude-johnson-v-4-v-6-loop-charge-replaces-omc-394408-sierra-18-1222","provider":"Good Vibes Marina","version":"1.0","type":"link"}