Compression Test 30 PSI difference 25%

[Greg2011]

I have a 1988 Johnson 40HP with the Vro2 oil pump.
I have 4 questions:
I checked the compression: cylinder one has 120 PSI and cylinder 2 has 90 PSI, a 30 PSI difference or 25%!
The engine starts, runs from 1500 RPM to 5500 like it was brand-new. The only problem is: it dies at idle when I set the idle from 800 to 1200 RPM with the engine in gear?
The engine has about 800 engine hours on it.

1) How long do these engines normally last? (Piston and ring wear on block) = low compression!
2) Is this 30 PSI the cause of the bad idle below 1500 RPM?

Also this is a weird one, I was checking the timing with a timing light, cylinder 1 was at 4 degrees = (spec 3+/-1). When I re-started the engine it was 180 degrees out. I stop it and restarted it and it was back to normal! Did this several times, I touch nothing on the engine.
3) Was I drunk, or the book said the power pack could be bad. That is what controls timing.
4) Can these things run 180 degrees out of time?

Note on the poor idle while in gear problem:
Both carbs were rebuilt.
Fuel pump was OK (4 PSI) = new last year.
New plugs
Cleaned with Sea Foam while running
New Coil to cylinder 2 spark plug-weak
Other than the PSI difference I can find nothing wrong, and maybe the power pack problem if there is one, if the timing is really changing 180 degrees?

Thanks Greg

[boats.net]

That low PSI Cylinder can cause the engine to die out at low idle. Some twin cylinder engines will fire both cylinders spark at both top dead center compression and decompression. So yes they can run 180 out.