The engines for the 2005 CRF 50F to 230 F motorbikes all have two valves per cylinder and are air-cooled. The engines for the 2005 Honda CRF 250R to 450X models all have engines with four valves ...

CRF 230F, CRF 230L, CRF 250R, CRF 250X, and the much more powerful CRF 450R and CRF 450X. The 2008 Honda CRF is one of the more popular and successful dirt bikes used in track racing, especially ...