TB Bore Kit – 120cc
120cc XR100 & CRF100 Big Bore Performance Kit (58mm):

• Aluminum cylinder with steel sleeve
• High compression 58mm piston with rings, pin, & clips
• Head gasket kit

This affordable 120cc Big Bore Kit will make your XR100 or CRF100 a lot more fun to
ride by adding some much needed power, This kit does not require boring of the
case – simply bolt on and go!!

There are no installation instructions, but if you can replace your
piston, you can install this kit. If you don’t have any experience working on
your engine, we highly recommend the Clymer’s repair manual available in this
section. The parts are installed in the exact same manner as the stock Honda parts.

Replacement Parts

58MM Piston Kit

58MM Gasket Kit