{"product_id":"sierra-marine-fuel-pump-kit-for-johnson-evinrude-outboards-18-7800-replacement-seals-check-valves","title":"Sierra Marine Fuel Pump Kit for Johnson\/Evinrude Outboards — 18-7800 replacement seals \u0026 check valves","description":"\u003cp\u003e\u003cstrong\u003eThe Sierra 18-7800 Marine Fuel Pump Kit is a complete replacement parts set engineered to restore proper fuel-pump function on compatible Johnson and Evinrude outboard motors.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis kit supplies the precision-molded check valves, O-rings, and gasket needed to rebuild or refresh an existing fuel pump assembly. All components are manufactured to meet or exceed original-equipment fit and tolerance so they mate cleanly with the pump body and deliver reliable sealing and valve action. The 18-7800 is designed as a direct, interchangeable service kit for several common OE part numbers used on older and current outboard engines.\u003c\/p\u003e\n\n\u003ch3\u003eWhich parts are included in the kit and why they matter?\u003c\/h3\u003e\n\n\u003cp\u003eThe Sierra 18-7800 kit contains two check valves, two different O-rings, and a fuel pump gasket—each part plays a specific role in controlling fuel flow and maintaining a leak-free seal. Replacing worn valves and seals prevents fuel leaks, improves pump efficiency, and helps maintain consistent performance under load.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eTwo 18-7796 check valves — control one-way fuel flow inside the pump.\u003c\/li\u003e\n  \u003cli\u003eOne 18-7413 O-ring — seals a mating surface to prevent vapor or liquid leaks.\u003c\/li\u003e\n  \u003cli\u003eOne 18-7403 O-ring — second sealing point for reliable containment.\u003c\/li\u003e\n  \u003cli\u003eOne 18-0850 fuel pump gasket — replaces the pump-to-block seal to stop external leaks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this kit fit my Johnson or Evinrude outboard?\u003c\/h3\u003e\n\n\u003cp\u003eThe 18-7800 is intended as an interchangeable service kit for several OE numbers, so compatibility is broad across many Johnson and Evinrude pumps. Confirm fit by matching your engine’s pump model or cross-referenced OE part numbers before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eInterchanges with GLM 40850, Evinrude\/Johnson 438616 and 433519, Mallory 9-37701.\u003c\/li\u003e\n  \u003cli\u003eWorks for pumps that use the same check valve and gasket layouts as those OE numbers.\u003c\/li\u003e\n  \u003cli\u003eCheck engine manual or remove pump cover to verify part shapes and dimensions.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do these components affect pump performance and maintenance?\u003c\/h3\u003e\n\n\u003cp\u003eWorn or hardened O-rings and failing check valves commonly cause fuel leakage, vapor lock, or inconsistent fuel delivery. Replacing the internal seals and valves restores airtight pathways and proper one-way valve action, reducing fuel-system failures and improving starting and throttle response.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eNew check valves restore correct pressure and flow direction inside the pump.\u003c\/li\u003e\n  \u003cli\u003eFresh O-rings and gasket renew sealing surfaces to eliminate leaks.\u003c\/li\u003e\n  \u003cli\u003eRoutine replacement during service intervals helps prevent roadside breakdowns.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat should I know about installation and service life?\u003c\/h3\u003e\n\n\u003cp\u003eInstallation is straightforward for anyone familiar with small-engine fuel systems; basic disassembly of the pump housing and careful reassembly with correct torque settings are required. Use compatible lubricants on O-rings during installation, inspect mating surfaces for damage, and replace any additional worn components to ensure long-term reliability.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFollow manufacturer torque and assembly guidance when reassembling the pump.\u003c\/li\u003e\n  \u003cli\u003eLightly lubricate O-rings with fuel-compatible grease for easier seating.\u003c\/li\u003e\n  \u003cli\u003eInspect pump diaphragm and housing for cracks—replace if deteriorated.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The Sierra 18-7800 kit is aimed at marine technicians, DIY boat owners, and service shops maintaining Johnson or Evinrude outboards that require OE-equivalent replacement valves and seals. It’s particularly useful when refreshing a fuel pump during routine maintenance or when troubleshooting fuel leaks and inconsistent engine operation. Verify compatibility with your engine’s pump model or the listed interchange numbers before purchase to ensure a proper match.\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: Does the 18-7800 kit match original equipment parts?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes—the kit meets or exceeds original equipment quality and interchanges with GLM 40850, Evinrude\/Johnson 438616 and 433519, and Mallory 9-37701.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I install this kit myself?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, with basic mechanical skills: disassemble the pump, replace valves and O-rings, lubricate seals, and reassemble to the manufacturer’s torque specs.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48086143926430,"sku":"B0009TU2FA","price":42.14,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/sierra-fuel-pump-kit-front-packaging_jpg.jpg?v=1785886570","url":"https:\/\/northtrailauto.ca\/products\/sierra-marine-fuel-pump-kit-for-johnson-evinrude-outboards-18-7800-replacement-seals-check-valves","provider":"North Trail Auto","version":"1.0","type":"link"}