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Im wondering if valve clearance will generally tighten or loosen over time? My bike has been hard to start lately, and running weird when warming up. Yesterday i couldnt even get the thing started and ive never not been able to start my bike. I figured maybe my valves  need to be shimmed. I bought the bike 2 years ago and have never shimmed the valves so maybe its time i thought. So i got the bike into the garage took the valve cover off, set it to TDC and checked my clearances using the same feeler gauges i used when i put a top end in the bike last year. The exhaust valves seem to have stayed about the same, but my intake valves are too tight for me to fit my feeler gauge into now. Im just wondering if this is normal, i would assume over time valves would get looser as opposed to tighter, but you never know so i thought id ask you all. 

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The valve seats wear causing the clearance to get tighter over time. Look at a blow up of your engine and you will understand. Valve and spring could be considered oriented "upside down". G

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When putting new shims in can one side of the intake or exhaust take a different size shim than the other side? i just put a pair of shims into my intake valves and the left side clearance is good around .12mm but my right side is around .17 mm, both with 2.40mm shims

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Yes it can be differnt sizes very normal from my exprience ive never seen them the same normal they are aroumd .05 mm difference hope that helps

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Each valve should be considered to be an individual.  They bear no real relation to each other with respect to wear and/or clearance.

A tight valve clearance means the valve is not closing properly which means compression is too low, which is what causes the hard starting.  Once the bike warms up, the metals will expand and restore the compression, which is why the motor will run fine with tight valve clearance.

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So im a bit frustrated. I  ordered a hotcams shim kit and the shims are seperated in .05mm increments. My left intake valve is fine, but my right side just wont get into spec. If i put a 2.45mm i cant fit my feeler gauge under it. If i put a 2.40mm under it i can fit a .152mm feeler gauge under it. In spec is anywhere from .10 - .15mm. Can i just run it .002mm out of spec until it tightens up a bit? Or Could that harm my engine?

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