Big bore kit for the 2003-2005 CRF150F. A simple bore in bore kit that includes BBR's high performance camshaft and valve springs for added performance. This cam features higher lift and duration than stock. Complete kit includes piston, rings, pin, clips, BBR MX cam, valve springs and gaskets. This is the quickest way to add the most power to your bike. Great when combined with our exhaust system, Rev-Box, and Free-Flow airfilter. Requires machining of stock cylinder for installation.