Lifter and Valve Questions

I'm rebuilding a 98' YZ400F. I've reached the point that I'm assembling the

head and needing to put in shims and lifters. Now the head is off of a 00'

WR and there were no shims with it when bought. I also only have 3 lifters

from the old YZ head. So my questions are which lifters do I purchase(Yellow

or Blue?) and where should I start shim wise? I know what the valve specs are ,but what do they come with stock? :)

It will be simpler to get the shimming sorted out while the head is still off on the bench. If you have any shims at all, select one in the range of say, 160 or 170, and put it in place on a valve. Put the lifter in place and set the cam in it's saddle, gently tapping the ball bearing down into it's seat with a soft faced mallet. Check the clearance while holding the cam down with your fingers or lightly snug the bolts to 1 or 2 ft pounds. This will get you a ballpark idea of which shim to use. Obviously, it can't be precisely right, but you'll be surprised how close it will get you. Your final selection should be checked with the head torqued down to the engine, and the cam caps properly torqued.

Hot Cams offers a shim kit for about $80 that has, I believe 3 of each size. Could be worth it.

The intake and exhaust lifters are two different sizes on some of the YZF's, but I am not sure on the head you are using. You can look Here to figure out what you need.

...thanks for the link Gray... :)

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