{"product_id":"heurofosh-exhaust-flapper-kit-807166a1-for-mercruiser-v6-v8-2-metal-rubber-flappers-with-grommets-oem-fit-anti-backflow","title":"Heurofosh Exhaust Flapper Kit 807166A1 for MerCruiser V6 V8 — 2 metal\/rubber flappers with grommets, OEM-fit anti-backflow","description":"\u003cp\u003e\u003cstrong\u003eThe Heurofosh 807166A1 Exhaust Flapper kit is a direct-fit replacement set of two marine exhaust flappers engineered to stop lake water backflow and restore proper exhaust sealing on compatible MerCruiser V6 and V8 stern drive engines.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eReplace worn or damaged exhaust flappers with this OEM-quality kit designed specifically for MerCruiser V6 and V8 engines that use the 807166A1-style shutter. Built from metal and rubber, the two flappers and included grommets aim to provide long-lasting resistance to corrosion and heat typical of marine environments. This product listing clarifies compatibility limits and installation notes so you can get the correct part the first time.\u003c\/p\u003e\n\n\u003ch3\u003eWhich MerCruiser engines will this 807166A1 kit fit?\u003c\/h3\u003e\n\u003cp\u003eThis kit fits many MerCruiser V6 and V8 stern drive models that use the 807166A1-style water shutter flapper. It is not universal: some V6s with one-piece manifolds and some early V8s with a round pin-through flapper require a different part.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIncludes two flappers plus four rubber grommets—part number 807166A1.\u003c\/li\u003e\n  \u003cli\u003eNot compatible with V6 engines that use one-piece manifolds—those require 807166A2.\u003c\/li\u003e\n  \u003cli\u003eDoesn’t fit early V8s that use a round pin-through flapper design.\u003c\/li\u003e\n  \u003cli\u003eCheck your current flapper shape and mounting pin style before ordering.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does installing these exhaust flappers affect engine protection?\u003c\/h3\u003e\n\u003cp\u003eThese flappers help reduce the chance of lake water being drawn into the exhaust when the engine is shut down hot, protecting internal components and exhaust passages. They act as a simple mechanical shutter that closes when flow stops, minimizing reverse water entry.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePrevents unwanted water backflow into manifolds and risers.\u003c\/li\u003e\n  \u003cli\u003eHelps reduce corrosion risk by limiting water contact with metal parts.\u003c\/li\u003e\n  \u003cli\u003eMaintains correct exhaust sealing for quieter, more efficient operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat materials and build quality should I expect from the Heurofosh kit?\u003c\/h3\u003e\n\u003cp\u003eThe kit combines durable metal for structural support with rubber grommets for a resilient, vibration-tolerant seal. Heurofosh aims to match OEM specs so fit and function closely resemble factory components.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMetal flapper blades resist heat and maintain shape under typical marine conditions.\u003c\/li\u003e\n  \u003cli\u003eRubber grommets provide cushioning and a water-tight seat for the shutter pin.\u003c\/li\u003e\n  \u003cli\u003eSold as a two-piece kit to replace both flappers simultaneously for balanced operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIs installation difficult and what should I know before fitting?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward for anyone comfortable with basic stern drive maintenance; the kit is designed for direct replacement using your existing mounting hardware. Always verify compatibility and follow safe procedures—work with a cool engine and proper supports.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRemove old flappers and inspect mounting pin and manifold for wear.\u003c\/li\u003e\n  \u003cli\u003eFit new rubber grommets, slide flappers into position, and secure per factory orientation.\u003c\/li\u003e\n  \u003cli\u003eTest with a brief engine run to confirm correct movement and sealing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The Heurofosh 807166A1 Exhaust Flapper kit is intended for boat owners, marine mechanics, and restoration specialists who operate MerCruiser V6 or V8 stern drive engines that match the 807166A1 shutter design. If you need an OEM-quality replacement to reduce water backflow risk and restore reliable exhaust shutter function—but please verify manifold and pin style before purchase—this kit provides a durable, straightforward solution.\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: Can I use 807166A1 on V6 engines with one-piece manifolds?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No. V6 engines with one-piece manifolds require part 807166A2 that has a flat tip; 807166A1 will not fit those manifolds.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does the kit include grommets and how many flappers are supplied?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The kit includes two exhaust flappers and four rubber grommets to replace both shutter assemblies.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Heurofosh","offers":[{"title":"Default Title","offer_id":48084596981918,"sku":"B0CG13YW9H","price":40.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/heurofosh-front-packaging-exhaust-flapper.jpg?v=1785860488","url":"https:\/\/northtrailauto.ca\/products\/heurofosh-exhaust-flapper-kit-807166a1-for-mercruiser-v6-v8-2-metal-rubber-flappers-with-grommets-oem-fit-anti-backflow","provider":"North Trail Auto","version":"1.0","type":"link"}