I originally posted an inquiry about this tractor on 3/27. Here is some followup: The tractor has a DH1101 engine and was run for likely a significant time with a quarter size hole in its air filter. Over time it became harder and harder to crank. When I finally checked the compression the first cylinder was very low (less that 100 psi) and the other two were about 200 psi. I pulled the head off and do not see an obvious problem. The tractor has a little over 2000 hours on it. There were slight ridges at the top of each cylinder but the rest of each cylinder appears to be smooth. What is the likely problem. I will have the head checked. Can I get by with putting new rings in the engine? Any suggestions are appreciated. Thanks.