{"product_id":"stainless-u-bolt-a4-aisi-316-50-90-mm-o10-m10-4boats","title":"Mercury Mariner Outboard Piston Kit 35-150HP 774-9137A11 18-4530 2.875\" Bore","description":"\u003c!-- \n  ***********************************************************\n  EBAY LISTING DATA\n  ***********************************************************\n  OPTIMIZED EBAY TITLE (80 Chars): Mercury Mariner Outboard Piston Kit 35-150HP 774-9137A11 18-4530 2.875\" Bore\n  SEO NOTES: Research-backed description for SKU 91371. Includes cross-reference to Sierra 18-4530 and Mercury 774-9137A11. Verified compatibility for 2-stroke engines.\n--\u003e\n\n\u003cdiv style=\"font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; line-height: 1.6; color: #333333; max-width: 900px; margin: 0 auto;\"\u003e\n\n  \u003cscript type=\"application\/ld+json\"\u003e\n  {\n    \"@context\": \"https:\/\/schema.org\/\",\n    \"@type\": \"Product\",\n    \"name\": \"Mercury Mariner Outboard Piston Kit - 35HP to 150HP\",\n    \"description\": \"Premium aftermarket piston kit for Mercury and Mariner 2-stroke outboard engines. Replaces OEM 774-9137A11 and Sierra 18-4530. High-silicon aluminum alloy construction for maximum durability.\",\n    \"brand\": { \"@type\": \"Brand\", \"name\": \"Aftermarket\" },\n    \"sku\": \"91371\",\n    \"mpn\": \"774-9137A11\",\n    \"offers\": {\n      \"@type\": \"Offer\",\n      \"url\": \"https:\/\/4boats.co.uk\/products\/91371\",\n      \"priceCurrency\": \"GBP\",\n      \"price\": \"{{ product.price | money_without_currency }}\",\n      \"availability\": \"https:\/\/schema.org\/InStock\"\n    }\n  }\n  \u003c\/script\u003e\n\n  \u003cdiv style=\"background-color: #2c3e50; color: #ffffff; padding: 40px 20px; text-align: center; border-radius: 6px 6px 0 0;\"\u003e\n    \u003ch1 style=\"margin: 0; font-size: 28px; letter-spacing: 1px; text-transform: uppercase; color: #ffffff;\"\u003ePiston Kit for Mercury Mariner Outboards\u003c\/h1\u003e\n    \u003cp style=\"margin: 10px 0 0; font-size: 18px; color: #ecf0f1;\"\u003ePrecision Replacement Part (SKU: 91371)\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"padding: 25px; border: 1px solid #e0e0e0; border-top: none; background-color: #ffffff;\"\u003e\n    \u003cp style=\"margin-top: 0;\"\u003eThis premium quality piston kit is engineered to provide a direct-fit replacement for Mercury and Mariner 2-stroke outboard engines. Specifically designed for the 35HP to 150HP range (1970–1990), this kit features a low-dome piston manufactured from a high-silicon content aluminum alloy. This material ensures exceptional thermal stability, reduced expansion, and extended service life in demanding marine environments.\u003c\/p\u003e\n    \u003cdiv style=\"background-color: #f8f9fa; border-left: 5px solid #27ae60; padding: 15px; margin: 20px 0;\"\u003e\n      \u003cstrong style=\"color: #27ae60;\"\u003eRELIABILITY:\u003c\/strong\u003e Engineered to meet or exceed original equipment (OE) standards, ensuring reliable engine compression and performance across the entire power range.\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"display: flex; flex-wrap: wrap; margin-top: 20px; gap: 20px;\"\u003e\n    \u003cdiv style=\"flex: 1; min-width: 300px; border: 1px solid #e0e0e0; border-radius: 6px; padding: 20px; background-color: #ffffff;\"\u003e\n      \u003ch3 style=\"color: #2c3e50; border-bottom: 2px solid #3498db; padding-bottom: 10px; margin-top: 0;\"\u003eKey Features\u003c\/h3\u003e\n      \u003cul style=\"list-style-type: none; padding: 0; margin: 0;\"\u003e\n        \u003cli style=\"padding: 10px 0; border-bottom: 1px dashed #eee;\"\u003e✔ Direct fit for 35-150HP 2-stroke models\u003c\/li\u003e\n        \u003cli style=\"padding: 10px 0; border-bottom: 1px dashed #eee;\"\u003e✔ High-silicon aluminum alloy material\u003c\/li\u003e\n        \u003cli style=\"padding: 10px 0; border-bottom: 1px dashed #eee;\"\u003e✔ Interchangeable with OEM components\u003c\/li\u003e\n        \u003cli style=\"padding: 10px 0; border-bottom: 1px dashed #eee;\"\u003e✔ Low-dome crossflow design\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"flex: 1; min-width: 300px; border: 1px solid #e0e0e0; border-radius: 6px; padding: 20px; background-color: #ffffff;\"\u003e\n      \u003ch3 style=\"color: #2c3e50; border-bottom: 2px solid #3498db; padding-bottom: 10px; margin-top: 0;\"\u003eTechnical Specs\u003c\/h3\u003e\n      \u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n        \u003ctr\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\u003cstrong\u003eBore Size:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0; text-align: right;\"\u003e2.875\" (Std) \/ 2.905\" (.030)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\u003cstrong\u003ePiston Type:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0; text-align: right;\"\u003eLow Dome\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\u003cstrong\u003eKit Includes:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0; text-align: right;\"\u003ePiston, Rings, Pin, Clips\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\u003cstrong\u003eApplication:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0; text-align: right;\"\u003e2-Stroke Outboard\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/table\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"margin-top: 30px;\"\u003e\n    \u003ch3 style=\"background-color: #34495e; color: #fff; padding: 12px 15px; margin: 0; border-radius: 6px 6px 0 0; text-align: center;\"\u003eCompatibility \/ Fitment Guide\u003c\/h3\u003e\n    \u003cdiv style=\"overflow-x: auto;\"\u003e\n      \u003ctable style=\"width: 100%; border-collapse: collapse; border: 1px solid #ddd;\"\u003e\n        \u003cthead\u003e\u003ctr style=\"background-color: #ecf0f1;\"\u003e\n\u003cth style=\"padding: 12px; border: 1px solid #ddd; text-align: left;\"\u003eEngine Type\u003c\/th\u003e\n\u003cth style=\"padding: 12px; border: 1px solid #ddd; text-align: left;\"\u003eCylinders\u003c\/th\u003e\n\u003cth style=\"padding: 12px; border: 1px solid #ddd; text-align: left;\"\u003eYear Range\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n        \u003ctbody\u003e\n          \u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e35 HP \/ 40 HP\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e2-Cylinder\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e1972 – 1989\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e50 HP \/ 60 HP \/ 70 HP\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e3-Cylinder\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e1973 – 1990\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e75 HP \/ 80 HP \/ 85 HP\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e4-Cylinder\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e1973 – 1986\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e90 HP \/ 115 HP \/ 140 HP\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e6-Cylinder\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e1970 – 1988\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003c\/tbody\u003e\n      \u003c\/table\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"margin-top: 30px;\"\u003e\n    \u003ch3 style=\"background-color: #34495e; color: #fff; padding: 12px 15px; margin: 0; border-radius: 6px 6px 0 0; text-align: center;\"\u003eOEM Cross Reference\u003c\/h3\u003e\n    \u003ctable style=\"width: 100%; border-collapse: collapse; border: 1px solid #ddd;\"\u003e\n      \u003ctr style=\"background-color: #fcfcfc;\"\u003e\n        \u003ctd style=\"padding: 12px; border: 1px solid #ddd; font-weight: bold;\"\u003eMercury \/ Mariner\u003c\/td\u003e\n        \u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e774-9137A11, 774-9137A10, 774-9137A9\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding: 12px; border: 1px solid #ddd; font-weight: bold;\"\u003eSierra Marine\u003c\/td\u003e\n        \u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e18-4530\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background-color: #fcfcfc;\"\u003e\n        \u003ctd style=\"padding: 12px; border: 1px solid #ddd; font-weight: bold;\"\u003eMallory Marine\u003c\/td\u003e\n        \u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e9-53401\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"margin-top: 30px; background-color: #fcfcfc; border: 1px solid #e0e0e0; border-radius: 6px; padding: 20px;\"\u003e\n    \u003ch3 style=\"color: #2c3e50; border-bottom: 2px solid #3498db; padding-bottom: 10px; margin-top: 0;\"\u003eQuestions \u0026amp; Answers\u003c\/h3\u003e\n    \u003cdiv style=\"margin-bottom: 15px;\"\u003e\n      \u003cp style=\"margin: 0 0 5px 0; font-weight: bold; color: #333;\"\u003eIs this a genuine original part?\u003c\/p\u003e\n      \u003cp style=\"margin: 0; color: #666; font-size: 15px;\"\u003eThis is a premium quality aftermarket replacement part, manufactured to meet or exceed original equipment (OE) standards for fitment and performance.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv style=\"margin-bottom: 15px;\"\u003e\n      \u003cp style=\"margin: 0 0 5px 0; font-weight: bold; color: #333;\"\u003eHow do I know if it is compatible?\u003c\/p\u003e\n      \u003cp style=\"margin: 0; color: #666; font-size: 15px;\"\u003eWe recommend checking your original part number against the cross-reference list provided above. This kit is specifically for the 3-port crossflow engines common in the 1970s and 80s.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv style=\"margin-bottom: 0;\"\u003e\n      \u003cp style=\"margin: 0 0 5px 0; font-weight: bold; color: #333;\"\u003eDo I need to replace all pistons at once?\u003c\/p\u003e\n      \u003cp style=\"margin: 0; color: #666; font-size: 15px;\"\u003eNo, this kit is designed with the same weight and balance as the original OEM components, meaning you can replace individual pistons as needed without necessarily replacing the entire set.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"margin-top: 30px; text-align: center; font-size: 14px; color: #7f8c8d; border-top: 1px solid #eee; padding-top: 20px;\"\u003e\n    \u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Please verify your original engine serial number and part number against the references above before purchasing to ensure correct fitment. Visit 4boats.co.uk for further assistance.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e","brand":"4Boats","offers":[{"title":"Default Title","offer_id":56755680608630,"sku":"91371","price":17.81,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0621\/8140\/9004\/files\/itm_91364__373_ba253a55-e446-4ea5-8faf-6e0f81772988.jpg?v=1764338584","url":"https:\/\/www.leighnumberplates.com\/products\/stainless-u-bolt-a4-aisi-316-50-90-mm-o10-m10-4boats","provider":"Leigh Number Plates","version":"1.0","type":"link"}