This 72cc big bore kit will fit the following models:

Honda:
-CRF50 and CRF70
-XR50 and XR70
-Z50R 1982-1999
Lifan:
-50cc and 70cc Motors
Zongshen:
-50cc and 70cc Motors

All other 50-70cc Pit Bikes and ATV's with replica Honda horizontal motors

Increase your displacement on 50cc models, or freshen up your tired 70cc top end. This is the only kit with a 47mm ALUMINUM cylinder on the market. Aluminum cylinders dissipate heat more efficiently and weigh considerably less than the cast iron competition. The included piston is slightly domed and will increase compression when used with 50cc cylinder heads. The kit is compatible with 70cc cylinder heads, but will yeild a lower compression similar to the stock Honda 70cc piston. Replacement parts are in stock if you need them.