Compression Test Results-- 1971 Johnson 50hp

[davedude]

This is one ugly motor. Kinda looks like junk. I have run it a couple times on muffs, first when I bought the boat/motor combo and then back home and it seemed to have good pop and ran ok. But I could spin the flywheel by hand easily which I took to be a sign of low compression. Well I put the compression tester on it yesterday evening and got 155psi on the top cylinder and 145 psi on the bottom cylinder. Cold, no prep, been sitting over the winter. I was surprised with that result, expected much lower and am now cautiously optimistic.
What is good compression for this motor? I have the service manual and unless I missed it there is no guideline for compression. 1971 Johnson 50 hp model 50ES71S.
Thanks for any comment.

 

[Crazyboat]

https://boatinfo.no/lib/evinrude/manuals/1971-1989johnsonevinrude.html#/32

I didn't have time to look up yours but I'm betting it's in the link. I know guys that report 120 being fine to run with but don't know if engines vary to worry about it.

 

[davedude]

Awesome link crazyboat, thanks very much for that. I'll give it a good look over this evening when I have more time. Looks like it might have much more info than in my specific service manual for the motor.
Do you think it is a safe bet the crank seals are leaking? Rings being good is one thing but seals is another and it looks like pretty much all the elastomer components are age hardened. Like the fuel lines, wow hard as a rock!