valve clearance is getting bigger

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

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.

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.

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. 

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!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Connor Wright
      Hey I have a crf250x 2005 I was riding today in top gear flat out and when I slowed down blue smoke just poured out the exsaughst then I happened to open the air box lid and saw it has what looked like engine oil in it then took out air filter and noticed that there was splatters of engine oil on the inside and that and the channel that goes to the carby had engine oil all over it.
      Also bike got a top end rebuild 15 hours ago
      The engine still runs good and sounds normal
      why would this be happening on a resonabley fresh engine
    • By mikemcbride
      Hey everybody. Quick question for y'all. I recently went riding and about halfway through my ride my motor seized on my '07 CRF250X. I haven't investigated it much but I checked the oil when I got home and there basically was none so I'm assuming that was the culprit. There weren't any metal shavings in the filter or on the plug either. At this point I'm trying to decide to rebuild the motor or just sell the bike as is and let the next buyer deal with it (they would know the deal obviously.) I feel that I'm pretty mechanically inclined but rebuilding a CRF engine is a bit out of my league and I assume paying a shop to do it would put me out more money than the bike is worth. So, I have this question to ask; what would be a fair price for a pretty dang nice shape 07 CRF250X, with a seized motor with an unknown extent of internal damage?
    • By ThomasM.
      selling Hot Cams Valve Shim Kit that i bought for my 2005 crf250x, will also fit crf250r.
      used 1x 1.30 and 2x 1.55 shims. the rest is still there.
      $60usd shipped in the usa or canada
      please contact me for pictures or if you are not sure if it will fit your bike
    • By TerryA
      I have two rides in on my new Rekluse auto clutch and I have to say I'm very pleased. The install wasn't hard, but was pretty much a all afternoon sort of project. I also installed a left hand rear brake kit and a two finger cluth over-ride with the adjuster on the perch (which I rarely seem to need). It has all worked great right from the beginning. After struggling to get up a tricky hill in first gear, I tried it in second and the autoclutch helped me clean the hill easily. Not having to worry about clutch action in techinical sessions has also eased fatigue and just made it more fun all the way around. I ride mountain bikes alot, and having both brakes up on the bars has also been nice as it makes for a set-up just like the bicycle - in fact I like that as much as not having to worry about clutch manipulation. The brake on the bar is especially nice on tricky downhill sections where you need to paddle, such as nasty rock/rut stuff. So first impressions are that it was worth the investment -making the ride more enjoyable and easier at the same time!
    • By Mikey560
      I was driving the bike for 15min or so and all of the sudden the bike stalled. I tried starting it again with no luck. I took the spark plug out to see if there is spark so i ground the spark plug to the frame and there is no spark. I even put a new spark plug in the bike and still nothing. Any ideas what i should check??