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valve clearance is getting bigger

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I have a 2006 with a A.P.E head with a 140hrs.When I checked my valve clearance, my exhaust went to .014 left and right and my left intake  went to .009 and right stayed at .006... the last time I checked the clearance was @ 117hrs and every thing was perfect. When I tear this down to replace the piston and rings, what should I focus on what the cause of  the clearance getting bigger...I do not ride this bike hard I trail ride and have fun, I change oil @ every 10hrs max and over clean my air box. Also do you guys think I should refresh the head if my cam,rocker arm are in specs???? thx for any input

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You should bounce those valves against the seats and try measuring again. Also check to see if they seal properly when closed. I’d suspect they don’t. Something is wrong.

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Common failure is the intake valves, most likely the right intake. When the clearance goes to zero the engine becomes difficult to start because of valve leakage. I got a whole summer out of mine by reshimming a few times.

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clearance getting LARGER would maybe be indicative of carbon build up on the valves/seats. You'll know when you get the head off. remove the valves and have a look at the seats. 

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clearance getting LARGER would maybe be indicative of carbon build up on the valves/seats. You'll know when you get the head off. remove the valves and have a look at the seats. 

A leak down test will also confirm this without having to tear things apart. Good luck!

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