Hoca 50cc QMB139 4-stroke 50mm, Racing Big Bore Cylinder Set. Kit includes cylinder, piston, rings, piston pin, cir clips, head gasket, and base gasket.Performance items are not returnable. Please see our Warranty & Returns Policy.
We recommend that you use our QMB139 performance cylinder head (see Related Items) with this set as some stock cylinder heads will not fit. Use with an un-modified stock head can cause serious engine damage.
*You may need to modify your engine case to accommodate the larger cylinder.