Need advice on valve shims- 99 YZ400F

I just checked my valves for the first time, and wanted to see what everyone thinks of my clearances.

Intake L to R- .15 .17 .20

Exhaust L to R- .25 .33

All but the one exhaust are within specs. I should probably tighten up the exhaust, right? How about the others, some are right at the end of the specs.

I recently valved my 2007 Kawasaki KLR, and everyone says slappy valves are happy valves for that bike. Is there any school of thought on the YZ's? Any idea if the valve shims from the KLR will fit in the YZ?


I don't know about the shims from a KLR but I used Hot Cams valve shims for a CRF450R from work on my YZ450F and they fit perfectly. I am old school and read in thousandths rather than millis so I can't think of what your clearances are off my head without a conversion and I'm not sure what your stock specs should be. If you are in spec with all but your one exhaust and its not out by much I would just ride it. The exhausts will tighten up slower than the intakes so just keep checking regularly and you'll be fine. Or if you feel like you wont sleep at night knowing one is off then adjust it, just kinda a pain in the ass on a twin camer for one exhaust valve if its not that bad, IMO.

Reshim the one exhaust valve that's out. You'll be good.

Thanks for the answers!

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