61mm Big Bore Cylinder Kit w/Head for 125cc – 150cc GY6 Scooters, ATVs, and Go Karts SPECIFICATIONS: Piston Diameter: 61mm Piston Pin Diameter: 15mm Piston Pin Length: 42.5mm Cylinder Head: Non-EGR COMPATIBILITY: Amigo – 150cc Scooters, ATVs Apollo – 150cc Scooters, ATVs, Go Karts Baotian – 150cc Scooters Baron – 150cc Scooters Bintelli – 150cc Scooters BMS – 150cc Scooters, ATVs, Go Karts Coolster – 150cc Scooters, ATVs, Go Karts Diamo – 150cc Scooters, ATVs Flyscooter – 150cc Scooters Gorilla Motor Works – 150cc Scooters Ice Bear – 150cc Scooters, ATVs, Go Karts Italica – 150cc Scooters JCL – 150cc Scooters, ATVs, Go Karts Jonway – 150cc Scooters Kandi – 150cc Scooters, ATVs, Go Karts Kinroad – 150cc Scooters, ATVs, Go Karts KMD – 150cc Scooters, ATVs, Go Karts Lance – 150cc Scooters, ATVs, Go Karts Leike – 150cc Scooters Linhai – 150cc Scooters Longbo – 150cc Scooters Motobravo – 150cc Scooters, ATVs, Go Karts Motofino – 150cc Scooters Motorino – 150cc Scooters NST – 150cc Scooters, ATVs, Go Karts Peace – 150cc Scooters Puma Cycles – 150cc Scooters Redstreak – 150cc Scooters Roketa – 150cc Scooters, ATVs, Go Karts Scootstar – 150cc Scooters Schwinn – 150cc Scooters SSR – 150cc Scooters, ATVs, Go Karts SUNL – 150cc Scooters, ATVs, Go Karts Supermach – 150cc Scooters, ATVs Tank Sports – 150cc Scooters, ATVs TaoTao – 150cc Scooters, ATVs, Go Karts Trailmaster – 150cc Scooters Veloz – 150cc Scooters Verucci – 150cc Scooters, ATVs, Go Karts Vitacci – 150cc Scooters, ATVs, Go Karts Viva – 150cc Scooters, ATVs, Go Karts Wolf – 150cc Scooters Xingyue – 150cc Scooters ZNEN – 150cc Scooters **NOTE: YOU WILL HAVE TO BORE OUT YOUR ENGINE TO COMPLETE INSTALLATION** 61mm Big Bore Kit for 150cc and 125cc GY6 4-stroke engines and converts it to 170cc. Crankcase modifications are needed for this cylinder kit. Increases displacement to 170cc! **