I checked my valve clearances yesterday (06CRF450R): .005 Intake both sides .010 Exhaust both sides .024 decomp (thousanths) At the bottom end of spec. But... The allowed tolerance for Honda is so small there is hardly room for human error, let alone wear. The average human hair is .006. So, .001 either way is such a small amount I have to wonder if this is what is contributing to the "supposed" valve concerns with Honda. I forget the tolerances for Yammies, but I know my YZ allowed for much more. My experience with bikes are only the ones I've owned, so I don't know what to think about this. The CRF is a precision machine no doubt, but it would have been easy to measure the exhaust at .009 and then go out and buy shims. .001 is a barely measurable difference. RHC, I would love to have your input on this.