Reshim with auto decomp cam???

If my valves are in spec now, will I have to reshim after installing the 03' yz450 ex cam??

Thanks, Dan

If my valves are in spec now, will I have to reshim after installing the 03' yz450 ex cam??

Thanks, Dan

If it is a 426, you will have change the shims.

If you're doing a cam change, you may not need to re-shim, but you have to check your tolerances to be sure...SC

Should I just throw the cam in, bolt it down and then check? Or should I run it then check? I know it sound stupid but thanks!

If my valves are in spec now, will I have to reshim after installing the 03' yz450 ex cam??

Thanks, Dan

To add to Devo's post above, if its a 400 OR 426 you will have to reshim with thicker shims - in the range of 1.95 to 2.05 mm if I remember correctly. Of course that will depend on how much your valves have already settled into their seats - thicker if there hasn't been much settling, thinner if there has. Dunno about the 450s - but probably not.

Should I just throw the cam in, bolt it down and then check? Or should I run it then check? I know it sound stupid but thanks!

You will have to shim...the base circle on the 450 cam is a bit smaller than the base circle on the 426...lift, duration, overlap, etc are the same.

Put the cam in, measure and reshim BEFORE you start the bike up...don't run it first. After you get it shimmed up right, run it for a bit, then check the clearance again.

Might as well check the intake too while you are in there. I figure if im going through the trouble to take stuff apart, I might as well replace as much as I can.

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