It's been a long time but there was a problem getting parts. First I took the head off and looked at the cylinder and valves. I thought the valves looked kind of burnt and I thought the cylinder didn't look so bad. But now I wish I had a good second opinion. Anyway , I hand ground the valves and am pretty sure I got a good seal when I was done and put new head gasket and fired it up....same problem. Won't even make 2000psi before engine is over worked. So I went back to the pump side and replaced valves and pressure seals, still same problem...I did a compression test and only get 60lbs max. But after a little more research, the motor is supposed to have an automatic compression release below 700 rpms ...So I went to harbor freight and bought a leak tester. I never used one before but following the instructions it tests in the green as far as percent air loss? ....I pulled the pump and I am going to try to get it tested at a pump shop to see if it can make 4k psi. I can rotate the pump shaft by hand . but it is stiff. The Kohler 15hp starts and sounds pretty good. Much easier to start without the pump ....I am going to try to get a rpm reading to see how fast it can go with no load and then try to get a reading under load.....If the pump can be tested and is good, I guess I'll have to open up motor and do cylinder and rings/piston....Has anyone heard of an auto de-compression getting stuck? What would the motor sound like? Any ideas or suggestions welcome, thanks.