Compression problem or nothing to worry about?

[Redneckhick]

Hi all
I have a 1976 Mercury 850 that I'm thinking about finding a pontoon boat to put it on. I did a compression test today #1 had 102 pounds and the other three had 110 on the nose. The water cover gasket also leaks around #1 but none of the others. I'm thinking the motor has been ran hot at some point over the years and #1 got the hottest. Do you guys think it is enough to worry about on a motor this old? Thanks

 

[PHE]

Re: Compression problem or nothing to worry about?

That's within 10%, but I would decarb the motor and see if #1 comes back up. If you look in the FAQ there is a good procedure. Carbon causes the rings to stick, and eventually will push the rings out enough to break them causing serious damage.

 

[Redneckhick]

Re: Compression problem or nothing to worry about?

Thanks just went and got some Seafoam this afternoon.