Valve shims measurements

[RJriver]

I have measured all my shims, and dont really understand why most of the measurements are less than the allowed tolerances. I have measured many times, know where the lobs are to be. Here are the specs:

Intake 1# .229mm 2# .089mm 3# .203mm, 4# .102mm

tolerance range .160mm to .200mm


Exhaust 1# .110mm 2# .229mm" 3# .152mm 4# .190mm

tolerance range .210mm to .250mm


# 3 intake i will probably leave alone and #2 exhaust is ok

I just dont get it , do i have another problem? why did I take things apart, i had a ticking sound, that was my boss's first reaction was that it was time to adjust valves It comes from the top of engine.
The only difference from last year was that I put in just regular mc oil where as last year I had in Amsoil, which I plan to put back in before long trip out west.
engine has 58,00, ran great last year and the couple of times this spring. I have done no major or minor engine work on it, no messing around
Any suggestions welcomed....

[Tat2demon]

A leaky exhaust gasket sounds very much like a noisy valve too.

I would get all your valves within spec first, re-tune/synch your carbs (have to after reshimming) and see how the sound is. Make sure all your headers are tight.

[RJriver]

thanks for the help,will check those things out..

I had gotten just 2 shims out last night. What a bear using that yami tool ! it just would not catch the valve guide edge,I worked for 2 hours just for thiose two shims, ugh
thought i would put them back in today, but no go. Cannot catch guide edge When i rotate the cam now the lob catches on the valve guide. very frustrate,

printed off that pictorail on lifting off cams, lloks like that is the only way now

thanks , how I love this adventure

[natemoen]

The tolerances get SMALLER in these engines as the valves ware INTO the head. As the valves ware then the valves open wider and wider and wider until they either hit a piston or do not close at all and you loose all compression.

These engines have a loud top end. They rattle and do make a lot of noise

[jjz28]

SO, when you check your shims, they get tighter instead of looser? I don't understand how you would put in a smaller shim. Seems like the cam wears and that's why you reshim it. I don't know much about motorcycle engines though and will be checking my shims soon.

[GLoweVA]

SO, when you check your shims, they get tighter instead of looser? I don't understand how you would put in a smaller shim. Seems like the cam wears and that's why you reshim it. I don't know much about motorcycle engines though and will be checking my shims soon.

Jeff, the cam don't wear as much as the seat that the valve sits in. As time goes on, the vavles seats a little deeper into the head and the valve stem/bucket gets closer to the cam, thus the need for smaller shims as time goes on.
That being said, when you go to put new ones in, size them so you're on the high side of the spec, this gives you more miles/years before the next shim change.

Like others have said, the top end of these machines can be a little 'noisy' with all that tapping going on, but the cams and the shims are tough (metal wise) and all will be well.