Scooter Big Bore Performance Kit, Fits The QMB139/GY6 Based 50cc Four Stroke Chinese Scooter Engines. This is a 50mm Bore, Comes Complete with Cylinder, Piston Set, Gaskets, Complete Head Already Assembled (64mm Valve Length), Performance Air Filter, Performance A 9 cam , Performance Variator with 6.5 Gram Roller Weights, 50cc 20mm carburetor, #80, #85 , #90 carb jets for fine tuning your engine Very Nice Performance. Exhaust , (64mm) Rocker arms , Performance CDI Box , Intake spacer , o ring , Fuel filter , Ignition Coil , Fuel Valve, 2000 rpm torque springs. The item "Scooter Big Bore Kit 100cc 50mm QMB139 GY6 Scooter Performance Parts Stainless" is in sale since Monday, November 19, 2018. This item is in the category "eBay Motors\Parts & Accessories\Scooter Parts\Other Scooter Parts".The seller is "scooter-parts1" and is located in Statesville, North Carolina. This item can be shipped worldwide.