{"product_id":"sierra-international-18-7844-fuel-filter","title":"Sierra International 18-7844, Fuel Filter","description":"\u003cp\u003e\u003cstrong\u003eThe Sierra International 18-7844 is a short, 21-micron marine fuel filter designed to replace Mercury part numbers 35-807172 and 35-802893Q while delivering 90 GPH flow for dependable engine fueling.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis compact fuel filter from Sierra is built for small to mid-size outboard systems that require a high-flow, sub-25-micron element. It’s engineered to trap particulate contamination commonly introduced by ethanol-blended gasoline, while maintaining consistent fuel delivery at up to 90 gallons per hour. The unit uses a short-body design (listed as 3875\" or 984mm) and a matching thread specification for straightforward OEM-style replacement.\u003c\/p\u003e\n\n\u003ch3\u003eHow does the 21-micron rating affect engine protection?\u003c\/h3\u003e\n\u003cp\u003eA 21-micron element captures medium-size particles that can wear injectors, carburetors, and fuel pumps without restricting normal fuel flow. It’s a balance between fine filtration and maintaining a high flow rate for hungry outboards.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eTraps sand, rust, and larger particulate down to 21 microns\u003c\/li\u003e\n  \u003cli\u003eReduces abrasive wear on fuel system components\u003c\/li\u003e\n  \u003cli\u003eHelps maintain consistent performance in marine environments\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this filter work with Mercury engines requiring part 35-807172?\u003c\/h3\u003e\n\u003cp\u003eYes — the Sierra 18-7844 is specified as a direct replacement for Mercury Marine OEM 35-807172 and also fits 35-802893Q applications. It matches the form, fit, and functional needs for those models so you can swap it into existing mounts and lines.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOEM cross-reference: MERCURY MARINE 35-807172\u003c\/li\u003e\n  \u003cli\u003eCompatible with applications calling for 35-802893Q\u003c\/li\u003e\n  \u003cli\u003eDesigned for like-for-like installation without custom adaptors\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does this filter handle ethanol-blended fuels?\u003c\/h3\u003e\n\u003cp\u003eEthanol in modern gasoline tends to attract and hold water and can loosen deposits that then circulate in the fuel system. The Sierra element helps remove loosened particulates, protecting downstream components and reducing clogging risk compared with no filtration.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCaptures particulates stirred up by ethanol and moisture\u003c\/li\u003e\n  \u003cli\u003ePrevents larger debris from reaching injectors and pumps\u003c\/li\u003e\n  \u003cli\u003eSupports reliable engine starts and consistent running\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the key physical and performance specs to know?\u003c\/h3\u003e\n\u003cp\u003eThis short filter is built to provide reliable flow and a correct mechanical interface with compatible Mercury systems. It balances a compact size with the capacity needed for many marine fueling demands.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFlow rate: 90 GPH to supply high-demand motors\u003c\/li\u003e\n  \u003cli\u003eFilter rating: 21 micron for medium-level particle capture\u003c\/li\u003e\n  \u003cli\u003eFilter size: Short - listed as 3875\" or 984mm (use OEM fitment as guide)\u003c\/li\u003e\n  \u003cli\u003eThread pitch: 42690 to match standard mounting\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? The Sierra International 18-7844 is aimed at boat owners, mariners, and service technicians who maintain Mercury-compatible outboards and need a compact, high-flow replacement filter that handles ethanol-blended fuels. It’s suited for routine service intervals, pre-season maintenance, or anytime a direct OEM-equivalent replacement is required to keep fuel systems clean and engines running reliably.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is the Sierra 18-7844 a direct replacement for Mercury 35-807172?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The Sierra 18-7844 cross-references Mercury Marine part 35-807172 and fits the same mounting and thread specifications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What flow rate and micron rating does this filter provide?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: It delivers up to 90 GPH and uses a 21-micron element to capture medium-sized particulates.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48086859186334,"sku":"B0001CLG2S","price":30.18,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/sierra-18-7844-front-view.jpg?v=1785908267","url":"https:\/\/northtrailauto.ca\/products\/sierra-international-18-7844-fuel-filter","provider":"North Trail Auto","version":"1.0","type":"link"}