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how to inspect intake/exhaust valves.

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hey i own a 05 crf250x and think i may have bad valves. i pulled the head off and noticed that there is alot of carbon buildup on the top of the piston and around the valves. does this meen i need replacing? i was wondering how you could check for bent or worn out valves to see if they need replacing.

please help thanks

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Mine looks like that too. I believe its normal. Did you check the clearance via feeler gauge before disassembly? Whats the problem you were experiencing?

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well at first it wouldnt start so i checked the clearences then i reshimmed it. then i went to ride it and it started the first time but then i went to ride it again and it wouldnt start unless i bomb started it. i took it apart to look at the valves and there is alot of carbon build up everywhere. and also i can take the piston and wiggle it back and forth a little bit. is that normal?

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pull the valves out and look at the angles. If they are cupped, they're toast.

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If the valves are submirged in their seats, they are cupped. You should be able to snag the valve with your fingernail if good as the valve with stick up a bit. Sounds like you need new intakes and possibly a new piston and rings. Oh, don't put that head back on without a new gasket. Carbon buildup is normal.

This is cupped Click Me!

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typically excessive carbon build up is a result of bad rings. If you valves are moving like that you need to have the seats cut and put new valves in.

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