I have an h23 and I just pulled a compression test, pistons 1,2,and 3 have 200 lbs, and piston 4 has 95. I thought it might have bad valves so I replaced all 4 valves for that cylinder and it made no difference. The cylinder walls are flawless, and it holds compression without leaking. Any ideas for possible problems or other good tests to help trouble shoot would be appreciated Thanks!

and yes, I did search for compression threads but didn't find anything helpfull.