88 johnson 120 re-ring?

[muddyfishin]

after a couple decarb sessions, ive still got only 90 psi in one cylinder, rest are 120, before the decarb it was at 80, but now ive got to move on to fix the issue,, pulled the head today to inspect , pretty smooth and really no wear on the walls, cpuld see some marks but nothing you could feel running your finger over it, wondering if i should tear it down and do the rings, never tore a power head down like that doesn't seem bad but looking for some input,, also could it possibly be that only a small section on the head gasket let go? i had a loose spot but culdnt determine if it was from when i smacked the head free as it was in the area,, any input on this project would be great thanks