Mercury 115 low compression top cylinder

[medic28640]

I have just bought a ski boat with a 77 Merc 115 outboard. I have been told it has low compression in it's top cylinder after a water pump failure. I had intended to replace this motor with a 115 Johnson that a friend of mine has. After hearing this motor start and run well, it has me wondering if I should consider fixing it before I sell it for parts or as a fixer-uper. The motor seems well looked after otherwise. Can I run this motor safely as is? Will I make it a more costly repair if run as is?

 

[ob]

Re: Mercury 115 low compression top cylinder

First thing I recommend you do is to find out what the readings were or obtain a new set of compression readings and see what they in fact are.There may not be a problem if the engine runs as well as you say it does.