Blue Line Big Bore Kit w/ Head 4T (72cc, 64mm Valves); QMB13

Complete 72cc Iron cylinder & head kit!!! This works with most Chinese 50cc 4-stroke 139QMB engines.Pump up that weak engine to a respectable 72cc displacement, on a budget. This kit is not indended to make your scoot a screaming race-machine. It is intended to get you that extra power you need. (Most Chinese 50cc's only put down around 1.5hp to the ground.)Increase the reliability & power of your scoot today!!*This kit includes the piston (not pictured) NOTE:Remove your valve from your scooter's head and meaure the full length of the valve stem. Some scooters like Znen(Wolf Brand, GMW, Bintelli, etc), Kymco 50cc 4T(Agility), some newer TaoTao and other 50cc 4-stroke scooters may have 69mm valve stem length. For these applications part number 1100-1515.This product is not intended for use on public roads or land.