{"product_id":"big-bore-gy6-cylinder-rebuild-kit-with-large-valve","title":"Big Bore GY6 Cylinder Rebuild Kit With Large Valve Head For 139QMB 139QMA And 147QMD Scooters Mopeds ATVs And Go Karts 69mm Long Valve Heads For More Power And Performance","description":"\u003cdiv\u003eGY6 69mm Big Bore Kit with Large Valve Head (1 kit) \u003cbr\u003e\n✔️ 69mm long valve head kit for 139QMB\/139QMA\/147QMD engines boosts power \u003cp\u003eThis Big Bore Cylinder Rebuild Kit upgrades the GY6 engine with a 69mm long valve head to increase horsepower and torque for scooters, ATVs, go-karts, and mopeds. It's designed for 139QMB, 139QMA, and 147QMD platforms commonly found in lightweight riders and off-road machines. Includes large valve head and compatible components; note that the engine side cover gasket is for the short-case 8-bolt version.\u003c\/p\u003e ✅ 69mm long valve head compatible with 139QMB\/139QMA\/147QMD engines\u003cbr\u003e\n✅ 18.5\/20.5mm large valve head vs stock 16\/18.5mm\u003cbr\u003e\n✅ Glixal piston rings with DLC wear-resistant coating to cut friction and protect the cylinder sleeve\u003cbr\u003e\n✅ Rocker arms compatibility: if original head uses 64mm valves, swap to kit's rocker arms\u003cbr\u003e\n✅ Engine side cover gasket included for short-case 8-bolt version\u003cbr\u003e \u003cp\u003e💡 What is a big-bore cylinder rebuild kit used for in GY6 engines? This handy upgrade improves power and throttle response for everyday riding. \u003cbr\u003e- Increases displacement and improves airflow with a larger valve head\u003cbr\u003e- Enhances torque for hill climbs and quick acceleration\u003cbr\u003e- Reduces friction with DLC-coated piston rings to protect cylinder wear\u003cbr\u003e- Fits 139QMB\/139QMA\/147QMD scooter, ATV, and go-kart engines\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amazon","offers":[{"title":"Default Title","offer_id":48203441602795,"sku":"VXB0C9X3X7H8","price":160.87,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0662\/3268\/0683\/files\/71yGp98-hsL.jpg?v=1778809550","url":"https:\/\/vxb.com\/products\/big-bore-gy6-cylinder-rebuild-kit-with-large-valve","provider":"VXB Bearings","version":"1.0","type":"link"}