{"product_id":"677-11181-a0-cylinder-head-gasket-for-yamaha-mariner-6hp-8hp-6b-8b-jlm-marine","title":"677-11181-A0 Cylinder Head Gasket for Yamaha Mariner 6HP 8HP 6B 8B | JLM Marine","description":"\u003ch2\u003eCylinder Head Gasket – Fits Yamaha Mariner 6HP 8HP 6B 8B 2-Stroke Outboards\u003c\/h2\u003e\n\n\u003cp\u003eThis aftermarket \u003cstrong\u003eCylinder Head Gasket\u003c\/strong\u003e is engineered for \u003cstrong\u003eYamaha and Mariner 6 HP and 8 HP 2-stroke outboard engines\u003c\/strong\u003e, including models \u003cstrong\u003e6B and 8B\u003c\/strong\u003e with serial numbers starting with \u003cstrong\u003e677\u003c\/strong\u003e. Designed to deliver reliable sealing performance, this gasket ensures proper compression and prevents coolant or combustion leaks in your outboard motor.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDirect replacement\u003c\/strong\u003e for Yamaha OEM part numbers \u003cstrong\u003e677-11181-A0-00\u003c\/strong\u003e, \u003cstrong\u003e677-11181-A1-00\u003c\/strong\u003e, \u003cstrong\u003e677-11181-01-00\u003c\/strong\u003e, and \u003cstrong\u003e677-11181-00-00\u003c\/strong\u003e, offering a cost-effective solution without compromising on quality or fitment.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003ePrecision-cut for accurate fitment on 6HP and 8HP 2-stroke models\u003c\/li\u003e\n  \u003cli\u003eManufactured to OEM specifications for consistent sealing performance\u003c\/li\u003e\n  \u003cli\u003eSuitable for routine maintenance and cylinder head reassembly\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Cross-Reference\u003c\/h2\u003e\n\n\u003cp\u003eUse this table to confirm equivalent part numbers across OEM and aftermarket sources.\u003c\/p\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse:collapse; width:100%;\"\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eBrand\u003c\/th\u003e\n      \u003cth\u003ePart Number\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e677-11181-A0\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e677-11181-A0-00\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e677-11181-A1-00\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e677-11181-01-00\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYamaha\u003c\/td\u003e\n      \u003ctd\u003e677-11181-00-00\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eCompatible Engine Models\u003c\/h2\u003e\n\n\u003cp\u003eConfirm your engine model\/year in the table below. For Yamaha owners, here's a guide to help you identify your engine's serial\/model: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/serial-number-guide\/yamaha-outboard-serial-number-guide-2025\" rel=\"nofollow noopener\" target=\"_blank\"\u003eYamaha Serial Number Guide\u003c\/a\u003e. You can also review exploded diagrams to verify part numbers: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/serial-number-guide\/yamaha-outboard-parts-diagrams-catalog\" rel=\"nofollow noopener\" target=\"_blank\"\u003eYamaha Parts Diagrams \u0026amp; Catalog\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n  \u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse:collapse; width:100%;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eNotes\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e6B\u003c\/td\u003e\n        \u003ctd\u003e6 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eEngines with SN starting with 677\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e8B\u003c\/td\u003e\n        \u003ctd\u003e8 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eEngines with SN starting with 677\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e6B\u003c\/td\u003e\n        \u003ctd\u003e6 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eEngines with SN starting with 677\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMariner\u003c\/td\u003e\n        \u003ctd\u003e8B\u003c\/td\u003e\n        \u003ctd\u003e8 HP\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003eEngines with SN starting with 677\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse:collapse; width:100%;\"\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eSpecification\u003c\/th\u003e\n      \u003cth\u003eValue\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003ePart Type\u003c\/td\u003e\n      \u003ctd\u003eCylinder Head Gasket\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eApplication\u003c\/td\u003e\n      \u003ctd\u003eYamaha Mariner 6HP 8HP 2-Stroke Outboards\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eOEM Part Number\u003c\/td\u003e\n      \u003ctd\u003e677-11181-A0\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eMaterial\u003c\/td\u003e\n      \u003ctd\u003eComposite Gasket Material\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eAftermarket\u003c\/td\u003e\n      \u003ctd\u003eYes\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\n\u003cp\u003eYour purchase includes:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\u003cspan style=\"color:red;\"\u003e\u003cstrong\u003e1 × Outboard Cylinder Head Gasket\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisconnect the spark plug wire\u003c\/strong\u003e to prevent accidental engine start during service.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRemove the engine cowling\u003c\/strong\u003e and locate the cylinder head assembly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnbolt and carefully lift the cylinder head\u003c\/strong\u003e from the engine block. Take care not to damage the mating surfaces.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRemove the old gasket\u003c\/strong\u003e and thoroughly clean both the cylinder head and block surfaces with a gasket scraper and solvent to remove all residue.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInspect the mating surfaces\u003c\/strong\u003e for warping, cracks, or damage. Resurface or replace components if necessary.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePosition the new cylinder head gasket\u003c\/strong\u003e onto the engine block, aligning all bolt holes and coolant passages carefully.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlace the cylinder head\u003c\/strong\u003e back onto the gasket, ensuring proper alignment with dowel pins if present.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInstall head bolts\u003c\/strong\u003e finger-tight in a crisscross pattern starting from the center outward.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTorque the head bolts\u003c\/strong\u003e to manufacturer specifications in multiple stages using a torque wrench, following the recommended sequence.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReconnect all coolant hoses, fuel lines, and electrical connections\u003c\/strong\u003e that were removed during disassembly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReinstall the engine cowling\u003c\/strong\u003e and reconnect the spark plug wire.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStart the engine and check for leaks\u003c\/strong\u003e around the cylinder head gasket area. Allow the engine to reach operating temperature and inspect again.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How do I confirm this gasket fits my Yamaha or Mariner engine?\u003c\/strong\u003e\u003cbr\u003e\nA: Verify your engine model is 6HP or 8HP 2-stroke (6B or 8B) with a serial number beginning with 677. Cross-reference the OEM part numbers listed above with your engine's parts diagram or service manual.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What are the signs that my cylinder head gasket needs replacement?\u003c\/strong\u003e\u003cbr\u003e\nA: Common symptoms include coolant leaks around the cylinder head, overheating, loss of compression, rough idling, white smoke from the exhaust, or coolant mixing with engine oil.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How often should I replace the cylinder head gasket?\u003c\/strong\u003e\u003cbr\u003e\nA: Replace the gasket whenever the cylinder head is removed for service, such as during top-end rebuilds, valve work, or if you notice compression or coolant leaks. There is no set interval—replacement is condition-based.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Should I use sealant with this gasket?\u003c\/strong\u003e\u003cbr\u003e\nA: Follow your engine manufacturer's specifications. Most modern composite gaskets are designed to seal without additional sealant. Applying sealant when not required can cause improper sealing or gasket failure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Can I reuse the old cylinder head gasket?\u003c\/strong\u003e\u003cbr\u003e\nA: No. Cylinder head gaskets are designed for one-time use and compress permanently during installation. Reusing a gasket will result in poor sealing and potential engine damage.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Is this an OEM or aftermarket part?\u003c\/strong\u003e\u003cbr\u003e\nA: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How fast do you ship and how much does it cost?\u003c\/strong\u003e\u003cbr\u003e\nA: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What is your warranty and return policy?\u003c\/strong\u003e\u003cbr\u003e\nA: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused \u0026amp; in original condition); please see our policy page or reach out for instructions.\u003c\/p\u003e\n\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003eVerify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.\u003c\/li\u003e\n  \u003cli\u003eThis product is an aftermarket replacement part and is not an OEM component.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended to ensure safety and optimal performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy Choose JLM MARINE?\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQuality Assured:\u003c\/strong\u003e As a trusted manufacturer for over 20 years, we supply top marine brands globally.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFast Global Shipping:\u003c\/strong\u003e Free delivery worldwide in 5–15 days.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDirect from Manufacturer:\u003c\/strong\u003e Competitive pricing without compromising quality.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"JLM Marine","offers":[{"title":"Default Title","offer_id":51981000147257,"sku":"23GT282","price":21.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0885\/0433\/6697\/files\/12_4c242291-5443-41dd-bccf-d1c7a6ce1d95.jpg?v=1772414144","url":"https:\/\/jlmmarine.com\/products\/677-11181-a0-cylinder-head-gasket-for-yamaha-mariner-6hp-8hp-6b-8b-jlm-marine","provider":"JLM Marine Boat Parts Limited","version":"1.0","type":"link"}