1980 115 hp cylinder pressure

[JimJamie]

As I stand behind the engine:

Cold.
Top left is 95 lbs
Bottom left is 102 lbs
Top right is 75 lbs
Bottom right is 94 lbs

At what point is an engine just not viable?
What problems arise that I might be seeing with low pressure?

[boats.net]

Shouldn't be more than 15% difference between cylinders, it's over that.

[phillnjack]

The 75 psi is the one to worry about.
BUT if it was me I would go buy a can of powertune by mercury, or the same stuff for Johnson or any other brand including seafoam etc and do a decarbonising job on all cylinders.
carbon can cause sticky rings not only in 2 strokes but also 4 strokes.
Now with outboard engines we don't all go at full throttle all the time.
This can cause rings to get a bit sticky and that can cause a severe drop in compression ,some just 1 cylinder and sometimes all cylinders.
I had a 60hp mercury that I though was running great, then I used power tune and done exactly what the instructiuons said, I was amazed at the power increase and noticed 10 psi increase on all 3 cylinders.
I gained around 5hp roughly and on a 60 that's a lot of extra oomph.
this stuff not only cleans the ring grooves but also all the combustion area.

DO NOT DO THIS NEAR A WHITE WALL OR GARAGE DOOR
the crap that comes out the exhaust is realy bad and is a nightmare to clean off, its a real load of smoke too so don't panic and don't call fire brigade ha ha
but the locals will all know your doing it that's for sure.

it realy does work and before any dis***embly I would try it.
I use it once a year as a rule just to keep things nice and clean anyway.

hope it helps you

phill