{"product_id":"sierra-18-7946-fuel-water-separator-filter-10-micron-replaces-omc-502905-omc-thread-marine-fuel-systems","title":"Sierra 18-7946 Fuel Water Separator Filter, 10 Micron, OMC Thread, Replaces OMC 502905","description":"\u003cp\u003eThe Sierra 18-7946 is a 10 micron fuel water separator filter built with an OMC thread configuration and a metal outer housing. It is designed to trap water and contaminants out of the fuel supply before they reach the engine, protecting fuel injectors, carburetors, and internal fuel system components from corrosion and debris damage. The filter uses a 1 inch-12 thread pitch for direct installation onto compatible fuel water separator housings.\u003c\/p\u003e\u003cp\u003eThis filter is part of Sierra's 10 micron OMC-thread filter line and directly replaces OMC 502905. It is intended for vehicle service on Mercruiser applications. Routine replacement of the fuel water separator filter helps maintain consistent fuel flow and protects against ethanol-related moisture contamination, a common issue in marine fuel 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 18-7946\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDescription:\u003c\/strong\u003e OMC thread\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMicron Rating:\u003c\/strong\u003e 10 Micron\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Pitch:\u003c\/strong\u003e 1 inch-12\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Material:\u003c\/strong\u003e Metal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1.09 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVehicle Service Type:\u003c\/strong\u003e Mercruiser\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282201876\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eVehicle service type: Mercruiser.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eOMC 502905\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the micron rating of the Sierra 18-7946 filter?\u003c\/strong\u003e The Sierra 18-7946 fuel water separator filter has a 10 micron rating.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-7946 replace an OMC part number?\u003c\/strong\u003e Yes, the Sierra 18-7946 directly replaces OMC 502905.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat thread size does the 18-7946 filter use?\u003c\/strong\u003e It uses a 1 inch-12 thread pitch, matching the OMC thread configuration it is built for.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the outer housing material of this filter?\u003c\/strong\u003e The Sierra 18-7946 has a metal outer housing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-7946 filter weigh?\u003c\/strong\u003e The Sierra 18-7946 fuel water separator filter weighs 1.09 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat vehicle service type is the 18-7946 filter used for?\u003c\/strong\u003e The Sierra 18-7946 is listed for Mercruiser vehicle service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many filters come in the package?\u003c\/strong\u003e The Sierra 18-7946 is sold as a single unit, one filter per package.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the difference between the 18-7946 and the 18-7846 filter?\u003c\/strong\u003e The 18-7946 is the 10 micron OMC-thread version, while the 18-7846 is the 21 micron version of the same OMC-thread filter design.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs there a Cobra EFI version of this filter?\u003c\/strong\u003e Yes, the 10 micron Cobra EFI equivalent to the OMC-thread 18-7946 is the Sierra 18-7989, which replaces OMC 502906.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-7946 a genuine Sierra part or aftermarket?\u003c\/strong\u003e The 18-7946 is a Sierra manufactured filter engineered as a direct replacement for OMC 502905, not an OEM-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does the 18-7946 filter protect against?\u003c\/strong\u003e As a fuel water separator filter, the 18-7946 removes water and contaminants from fuel before it reaches the engine's fuel system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I identify the 18-7946 filter by its UPC?\u003c\/strong\u003e Yes, the Sierra 18-7946 filter carries UPC 808282201876.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988391309531,"sku":"SIE-18-7946","price":10.32,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/XA__83590.1753840687.500.750.jpg?v=1785188920","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-7946-fuel-water-separator-filter-10-micron-replaces-omc-502905-omc-thread-marine-fuel-systems","provider":"Good Vibes Marina","version":"1.0","type":"link"}