72cc GY6 QMB139 Four Stroke Big Bore Kit For Moped Scooter ATV - 47mm Each kit includes: Milled Non-Emissions Head with 18mm diameter intake and 16mm diameter exhaust valves and high performance springs. Valves stems are 69mm long. Performance Camshaft IS included(most BB kits do not include a performance cam) with 5.00mm lift and 116 degree lift angle Non-Emission head In the picture the cylinder and head are shown from both the top and bottom for clarity only one set is included with this kit. 50mm OD barrel sleeve