Today I had some time to look at the motor again. I re checked compression in some of the cylinders #6 stayed the same at around 150 the others were even higher than before in the 240 range so I stopped testing. I think I mentioned before that I put marvel mystery oIL in each cylinder so I'm guessing that's causing the high numbers although I cranked the engine over several times before testing. I also did a leak down test on all cylinders here is what I found. #1 19% leaking through exhaust and rings #2 15% rings #3 30% rings/exhaust #4 18% rings/exhaust #5 25% oil/exhaust #6 55% exhaust #7 22% exhaust/rings #8 25% rings/exhaust. Im guessing with these results the heads need to be replaced?

It might just need a valve job, but you won't know until the valves are removed.

So a little update. I tore the engine apart and brought the heads to machine shop just waiting for an update and repair. I have everything cleaned and prepped to go back together but I'm a little unsure on the assembly. basically I'm looking for the torque#s and sequence of the heads and intake, adjusting the valves and possibly retiming the engine.

Was the exhaust seat in your comprimised cylinder corroded? And did you figure out the high compression test readings ? Prob want to find out what is going on before you have a exhaust valve head detach and bee bop around inside your motor

I'm not sure why the compression was so high the first time. the second time I had put mystery oil in each cylinder so that gave me a false reading. The heads were repaired I will be picking them up today. I was told that they were pretty bad but not sure what they repaired. I just hope this solves the reversion problem I've been having.

Im thinking you would have to pour mystery oil down the neck of your compression testor while your doing your test to achieve 240 on a contemporary marine engine. If reversion cooked your exhaust valves , and those boys slapped some low shelf valves in now , your not out of the woods yet