Valve shims 2012 CRF250R

pstorey942
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Algonac, MI US
pstorey942
I am currently working on a full top end rebuild. Brand new head, valves, and cam. I was wondering if any one would know what shim sizes I should start out with to get me close to clearance spec. I do have the shim kit. I am trying to avoid playing a bunch of guessing games, and having to take the cam in and out more than a few times.
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Paw Paw
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Paw Paw 7/21/2020 4:29am
7/21/2020 4:29am
Do your test fitting with the head on a work bench so that you don't have to deal with the cam chain and it will go a lot easier.

PawPaw
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kb228
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kb228 7/21/2020 5:13am
7/21/2020 5:13am
Test on the bench as pawpaw said.

I start with a shim thats too short so i have a gap to do my calculations off of. The only guessing you should be doing is finding a shim too short. After you find one its a matter of doing math to get the right shim.
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DynoDan22
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DynoDan22 7/21/2020 6:35am
7/21/2020 6:35am
I always remembered those year CRF250's using around 180-185 for the inlet and 205-210 for the exhaust when everything is new.
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pstorey942
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pstorey942 7/21/2020 11:26am
7/21/2020 11:26am
I didn’t even think of doing it on the bench. Thanks all!

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