03 YZ 450. Total Valve replacement, valves, springs, guides, head cleaned up by machinist etc. I assemble everything and on the intakes I am already down to a 160 shim at .10 & 155 on the exhaust at .20. Is it normal to have to run such low numbers on the shims right out of the gate on new valves? I guess I expected to be more towards the 200 range. Also, is there a rule to running them a little tighter or loose when they are new? Thanks in advance for any help.