Stupid Shim Question

[txtriathlete]

Measured all the cam/shim clearances when I had the cover off, all were tighter (closer) than what is spec'd. For some reason in my head I was thinking they should be higher (looser) than spec if they need to be adjusted - like a wear part wearing down a surface.

I recently read something somewhere (KZ1000 forum?) that made me think they might get tighter as they go out of spec? Which way do they wear - tighter or looser?

Either way it looks as if I am gonna be getting my shim on...got fire shooting out of the exhaust ports (pipes are off) when I turn it over...that can't be good...gotta check timing.

But it is running.

[tcoop]

As the valves where into the heads the gap gets tighter. So as the gap get tighter you need to change out to a smaller shim to set the gap into specs.

[Radioguylogs]

As Ty said, the shims get tighter as the valve seats wear, and you need to change to a 'thinner' shim.

My bikes seem to shift about 1 shim size very 10,000 miles.

[TopCatGr58]

Hey Tx,

If you didn't pull each shim after checking clearances, you will want to do that to document each ones sizes. Because sometimes you will find one that may work for another valve location, and therefore need to replace less than all 8.

T.C.

[MPittma100]

Maximum Gap

Set the clearances to the maximum spec. This will allow longer intervals between adjustments.

[myac455]

Mine were dead nuts on , on the exhaust cam.
3 of the four intakes were under a few thou .
Still at about .004 (We don't talk mm. here. I'd have to buy a new feeler gauge)
Anyone ever found a used bike @.000 , and the cam worn?
I figure I can get the bike going and ride it around some, and deal with it later.

[mack]

shimming

As a general rule of thumb. When these motors get quiet, it's time for a shim adjustment.

[myac455]

As a general rule of thumb. When these motors get quiet, it's time for a shim adjustment.

Thanks. Makes sense.
Never thought of it, seeing I only had mine running for 20 seconds, before I tore it all apart.