1973 65 hp Evinrude: Compression test completed, what does it mean?

[BigJ08]

Re: 1973 65 hp Evinrude: Compression test completed, what does it mean?

When the head was off, it should have been checked for true.(flatness) It is easy to flat sand and correct minor warp.

Possible the upper cylinder has not been receiving fuel as well s the lower 2 and worn the rings more. Still a usable motor though. If it is not missing at speed and not over laboring, you should still get a few seasons out of it before needing a rebuild.

Did you do a wet compression test?

What is a wet compression test?

 

[jay_merrill]

Re: 1973 65 hp Evinrude: Compression test completed, what does it mean?

What is a wet compression test?

Its when you inject a little oil into a cylinder via the spark plug hole. Use a squirt can and put about a teaspoon to a tablespoon of oil in it. The point of doing this is to check the condition of the rings - the oil will tend to seal the rings somewhat, so if you see a marked improvement in your top cylinder, chances are that you have worn rings.


???

 

[BigJ08]

Re: 1973 65 hp Evinrude: Compression test completed, what does it mean?

Ok thanks, have not done that.