Larry, On the O-200 I had the exhaust valve guide was busted up. This could cause you low compression. How about the oil temp? Is it ok? On mine it was fine in humid air or in the winter months. I would at least pull the exhaust off of the cylinders and do a visual on the valve guides. One more question, Are they millennium cylinders? I heard nothing but bad about them. You can get an overhaul kit for about 3k. I comes with 4 cylinders (from continental), and if you are an A&P you can sign off the overhaul as major.
Chris Theroux Gilbert, AZ
