# Probably a dumb question...

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Ok so this is probably a dumb question but here gos... My machine shop doesn't shim my valves after a valve job so it's up to me to handle that. What I've been doing is just sitting down with my shim kit and just swapping out shims trial and error style till I get my desired clearance. Is there a better/faster way I can do this??? Perhaps throwing the buckets on without shims, getting a clearance and doing some math formula???

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basic math dude. You have to know what shim you have in, what the clearance is and what you need the clearance to be. easiest way is an example. If the clearance is .028 and needs to be .025, you need a .003 larger shim then what is already in there. A larger shim decreases the gap and a smaller shim increases the gap.

Edited by Die_trying

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basic math dude. You have to know what shim you have in, what the clearance is and what you need the clearance to be. easiest way is an example. If the clearance is .028 and needs to be .025, you need a .003 larger shim then what is already in there. A larger shim decreases the gap and a smaller shim increases the gap.

Umm yeah I'm aware of that. But if there is no shims in the head after the valve job and I throw some in and get zero clearance I'm right back to swapping shims left and right till I get a clearance. That's not what I want to do. Follow me?

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Umm yeah I'm aware of that. But if there is no shims in the head after the valve job and I throw some in and get zero clearance I'm right back to swapping shims left and right till I get a clearance. That's not what I want to do. Follow me?

then, you put in the smallest shims you have because if you cant get a feeler gauge in there then the shim is too big. If it's still zero then check what the smallest you have is vs the smallest your mfg or after market makes.

Edited by Die_trying
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theres nothing wrong with how your doing it.  just takes a little more time, but in the end your valves still get shimmed, if you find it easier to go trial and error style go ahead.   ive used the same method before and it really doesnt take that much time to get the right shim in there

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Sounds like a lot of work!

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Most Japanese bikes have a chart that make it easy.  Just put in your shim and follow the column to your ideal clearance.  KTM you have do it all on your own

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^whut......

It helps A TON to have a micrometer, then just set them as loose as possible, and see what you need.

In theory, you'll need to take the shims OUT ONCE maximum, but that's not always life......

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Do you know what size shims came out of it? I mean, its not like its all the same after new valves, but it can be a starting point.