I am in the process of winter tear down. I bought this bike used earlier this year, good condition but no direct knowledge of its history. The valve clearance just a little tight, will install new shims. The cams at TDC, exhaust slightly left (counter clockwise) of perfect. Intake one tooth right (clockwise) of perfect. Its like previous owner did YZ timing but to the intake side. The cam chain seems like it may be a little stretched but not to bad. Can a cam chain stretch this much or did someone mess up previous installation. I will order new chain tomorrow just to be sure. The bike has run smooth and reliable but I have been looking for more low and mid range punch. I have been messing with jetting because of the deep sounding (rich) bog low to middle. Your thoughts. I have not ridden another thumper to compare, previous bike CR250.