Compression results

[AnkorCraft79]

1979 mercruiser 120, oil clear and clean, runs smooth and strong. Compression 1-135, 2-85, 3-125, 4-135 wet#2 85. Owner before me replaced frozen/broken manifold and I wonder if water got on valve or valve seat or just a burnt valve. Seen many head problems with these engines?

 

[Don S]

Re: Compression results

Do a leakdown test, then you will know what is leaking.

Seen many head problems with these engines?

No more than any other engine. Lots of things can cause low compression, water intrusion, timing,