{"product_id":"gy6-50cc-139qmb-scooter-39mm-50cc-cylinder-kit","title":"GY6 50cc (139QMB) Scooter 39mm 50cc Cylinder Kit","description":"\u003ch2\u003e39mm Cylinder Kit for GY6 50cc Scooters\u003c\/h2\u003e\u003cp\u003eThis 39mm cylinder kit is designed for a complete top-end rebuild on 50cc scooters that use the 139QMB engine. It suits scooters showing oil consumption, lost compression, or general wear, and gives you the parts needed for a fresh rebuild in one set. It is also one of the simpler \u003ca href=\"\/collections\/gy6-50cc-parts\"\u003eGY6 50cc scooter parts\u003c\/a\u003e to fit yourself at home.\u003c\/p\u003e\u003ch3\u003eWhat Comes in the Kit\u003c\/h3\u003e\u003cp\u003eThe package contains a cylinder, piston, piston rings, wrist pin, fasteners, dowel pins, and every gasket needed. Its stock 39mm bore matches the original components, so it drops in as a direct replacement with no modification. Gaskets for the head, base, and intake are all supplied, so the set is complete.\u003c\/p\u003e\u003ch3\u003eInstallation and Care\u003c\/h3\u003e\u003cp\u003eClean all gasket surfaces thoroughly before assembly. The new gaskets are included to help you achieve a proper seal. After fitting, follow a break-in period over the first miles to keep the engine performing as it should.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBore:\u003c\/strong\u003e 39mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisplacement:\u003c\/strong\u003e 50cc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Cylinder Height:\u003c\/strong\u003e 70mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder Sleeve Outer Diameter:\u003c\/strong\u003e 44.7mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Type:\u003c\/strong\u003e 4-stroke, air-cooled\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e Cylinder, piston, piston rings, wrist pin, 2 circlips, 2 dowel pins, head gasket, base gasket, intake gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Part Number:\u003c\/strong\u003e 151-257\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e 139QMB and 139QMA GY6 50cc 4-stroke engines (39mm bore, 44.7mm sleeve)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eCompatible with:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e139QMB GY6 50cc engines (codes 139QMB, 1P39QMB, YN139QMB, JJ1P39QMB, BD1P39QMB, BN139QMB)\u003c\/li\u003e\n\u003cli\u003e139QMA GY6 50cc engines (codes 139QMA, 1P39QMA-2)\u003c\/li\u003e\n\u003cli\u003eTao Tao scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eZNEN scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003ePeace Sports scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eIcebear scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eJonway scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eWolf scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eBaccio scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eBintelli scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eBMS scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eSchwinn scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003cli\u003eSunL scooters with 139QMB or 139QMA engines\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e Find the engine code stamped on your scooter and match it to 139QMB or 139QMA. Then confirm that your original cylinder measures 39mm bore and a 44.7mm sleeve diameter.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBrowse related parts:\u003c\/strong\u003e \u003ca href=\"\/collections\/gy6-50cc-parts\"\u003eGY6 50cc Scooter Parts (139QMB)\u003c\/a\u003e · \u003ca href=\"\/collections\/gy6-scooter-parts\"\u003eGY6 Scooter Parts\u003c\/a\u003e · \u003ca href=\"\/collections\/scooter-cylinder-kits\"\u003eScooter Big Bore \u0026amp; Cylinder Kits\u003c\/a\u003e · \u003ca href=\"\/collections\/scooter-parts\"\u003eScooter Parts\u003c\/a\u003e\u003c\/p\u003e","brand":"Trend Times Toy Stores","offers":[{"title":"Default Title","offer_id":51137940455481,"sku":"TT-23980","price":47.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0665\/3358\/9049\/files\/39mm-50cc-cylinder-kit-for-gy6-50cc-139qmb-scooters-1.jpg?v=1794369854","url":"https:\/\/www.trendtimes.com\/products\/gy6-50cc-139qmb-scooter-39mm-50cc-cylinder-kit","provider":"Trend Times Toy Stores","version":"1.0","type":"link"}