Glixal ATMT1-023 High Performance GY6 61mm 170cc Big Bore Rebuild Cylinder Kit For 152QMI 157QMJ Engine Chinese Scooter Moped ATV 1.Please Note: 61mm Bore Cylinder May Require to Machine the Crankcase on Some Engine Model 2.Please Note: This Cylinder fits the 76mm Bolt Pattern Engine, It will not work on the 80mm Bolt Pattern 3.Outer Diameter of Piston Pin: 15mm 4.Inner Diameter: 61mm and Outer Diameter: 65mm 5.Include Cylinder,Piston,Piston Ring,Piston Pin,Piston Pin Clip,Valve Oil Seal,Gaskets,Tensioner Gasket,Exhaust Gasket,Intake&Exhaust Studs,Exhaust Nut