- Mar 6, 2002
I have read a lot about CRF450 valves and the inspection and adjustment frequency. Is this a problem that should be addressed with replacement valves etc. or is it just a normal maintenance issue that you need to live with on a high-stepping 4-stroke MX bike? Most of my riding will be C-grade/Vet MX racing and more in the mid-range rather than lots of high-rev work.