compression test

Should compression be checked cold or hot? Add oil or not? I did a dry, cold test and was not impressed w the results. 105 to 125 between them all. Gonna try another guage to be sure. I just re-rung this engine less than 1000 miles ago. Gonna try a leak down test as well.

Warmed up. Dry and wet, helps diagnose the issue. Leakdown is best when compression is low, then you can determine where the biggest loss is per cylinder. But if you have say a bad valve, it will tell you that of course, but then won't really show ring leakage that may be there as well. Bad oil rings won't show on either test. Remember a fully charged battery, and the Throttle wide open during compression testing.

warm the engine up to normal operating temp. open throttle fully

Wot! Gotcha. Didn't do that. Had a guy cut the seats for me and be told me not to lap them in. It's got about 16000 on the clock. Hope the bores arent ovaled

They always tell you not to lap the valves in after they cut the seats, and I always lap them.

I've proved to my own satisfaction that it is worth doing.