Time1992 Posted April 2, 2009 Posted April 2, 2009 I thought I had all the tune up data etc. but I cant find anything on doing a valve adjustment. The engine has a light knock and I am curious if this might be the problem. Thanks, Tim its on my 73 4041
BenB Posted April 4, 2009 Posted April 4, 2009 Tim, My manual shows the valve clearance is the same on CCK,CCKA, and CCKB Onans. With the engine cold, intake is 0.007 and the exhaust is 0.016 Please post back and let us know if the adjustment stopped the noise. Hope this helps, Ben
Time1992 Posted April 4, 2009 Author Posted April 4, 2009 Thanks Ben, does it talk about how to do it ? There should be some sort of sequence or something. Tim
D-17_Dave Posted April 5, 2009 Posted April 5, 2009 When adjusting the valves on any small engine adjust them with that cyl. on it's compression stroke and at TDC. This will insure the cam lobes are putting no pressure in the lifters. I dought the valves are loud enough to cause any noise. Hows the oil pressure? Does the noise stop when you push in the clutch? Indicating something loose in the clutch drive. Might also check the rear PTO. Could have the holes in the fiber disc egg shaped or worn rubber mount bushings in the spline drive. Could be time to pull the heads and look for carbon deposite or signs of a piston hitting the head.
Time1992 Posted April 5, 2009 Author Posted April 5, 2009 Replaced the clutch bearings and all is tight, pto componits are ok, but the carbon in the head idea might be it. It does get quieter when it warms up, Im afraid that could mean piston slap, ristpin or rod bushings ? It dosent smoke and comp. is real good.
D-17_Dave Posted April 5, 2009 Posted April 5, 2009 Normally on internal engine parts a noise gets louder when it warms up due to the oil viscosity getting thinner. If the noise lowers when warm I'd say it's time to pull the heads for sure. Hope that's all it is.dOd
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