High Performance 80cc 50mm Big Bore Cylinder Kit for 50cc 4-Stroke 139QMB Scooters INCLUDES: Cylinder Block Piston Piston Rings Wrist Pin Circlips Gaskets COMPATIBILITY: Amigo – 50cc 4-Stroke Scooters Apollo – 50cc 4-Stroke Scooters Baotian – 50cc 4-Stroke Scooters Baron – 50cc 4-Stroke Scooters Bintelli – 50cc 4-Stroke Scooters BMS – 50cc 4-Stroke Scooters Coolster – 50cc 4-Stroke Scooters CSC – 50cc 4-Stroke Scooters Diamo – 50cc 4-Stroke Scooters Flyscooter – 50cc 4-Stroke Scooters Ice Bear – 50cc 4-Stroke Scooters Italica – 50cc 4-Stroke Scooters JCL – 50cc 4-Stroke Scooters Jonway – 50cc 4-Stroke Scooters Kandi – 50cc 4-Stroke Scooters Kinroad – 50cc 4-Stroke Scooters KMD – 50cc 4-Stroke Scooters Kymco – 50cc 4-Stroke Scooters Lance – 50cc 4-Stroke Scooters Leike – 50cc 4-Stroke Scooters Linhai – 50cc 4-Stroke Scooters Longbo – 50cc 4-Stroke Scooters Motobravo – 50cc 4-Stroke Scooters Motofino – 50cc 4-Stroke Scooters Motorino – 50cc 4-Stroke Scooters NST – 50cc 4-Stroke Scooters Peace – 50cc 4-Stroke Scooters Puma Cycles – 50cc 4-Stroke Scooters Redstreak – 50cc 4-Stroke Scooters Roketa – 50cc 4-Stroke Scooters Scootstar – 50cc 4-Stroke Scooters Schwinn – 50cc 4-Stroke Scooters SSR – 50cc 4-Stroke Scooters SUNL – 50cc 4-Stroke Scooters Supermach – 50cc 4-Stroke Scooters SYM – 50cc 4-Stroke Scooters Tank Sports – 50cc 4-Stroke Scooters TaoTao – 50cc 4-Stroke Scooters Trailmaster – 50cc 4-Stroke Scooters Veloz – 50cc 4-Stroke Scooters Verucci – 50cc 4-Stroke Scooters Vitacci – 50cc 4-Stroke Scooters Viva – 50cc 4-Stroke Scooters Wolf – 50cc 4-Stroke Scooters Xingyue – 50cc 4-Stroke Scooters ZNEN – 50cc 4-Stroke Scooters Aluminum big bore cylinder kit works on Schwinn, QLink, Diamo, Tank, Verucci, Roketa, Meitian and most scooters with GY6 139QMB 4T engines. Also do not forget your clutch, roller weights, and belt to use this new find power to better take off and no slip with Kevlar belts. Good size for roller weights for bottom end and not losing top end is 5 – 6 gram weights depending on rider’s weight. **NOTE: YOU CAN USE YOUR STOCK CYLINDER HEAD TO COMPLETE INSTALLATION. You will also need to break in scooter at 20-25 mph for the first 300 miles to allow engine to adjust accordingly.