CRF250 cam holder wear

[bro]

I recently bought a used '05 CRF250R and of course the previous owner said he took immaculate care of it. I am normally a very trusting person but when it comes to dirt bikes I have learned to trust no one, not even my mother.

So anyway, I pulled everything apart to check things out for myself. Most everything looked pretty good except for the cam bearing holders. There appear to be some wear marks on the bearing holder surfaces. Nothing real bad, just some discoloring, no big grooves. I am wondering if this is normal? Do the bearing housings actually rotate in the holders?

Just to be safe I do plan on replacing the piston, rings, valves and springs. However, the wear on the cam bearing holders has me a little concerned.

Thanks

 

[bwood]

I have an 05 also. I bought it new in Nov 05 and have also noticed some discoloration on the outer cam bearing races where they contact the cam holders. I have never worried about it, I wonder if it might be discoloration from oil sitting between the cam bearing and holder from servicing and just cooking. I have not noticed any premature wear in the bearing area. I check the valves about once a month and this discoloration appeared the second time I checked them (about Jan 06).