Mercury Compression

[Bigshrimpin]

Originally Posted by jorgeinmiami

I have a 1992 Mercury 200 Offshore outboard that I ran a compression check over the weekend.

All cylinders came out at 110 psi.

Im not sure if this is good or not.

What would be a indication or where should they be?

There are some 2.5L 200's that have lower compression. I'll check to see the number on the heads. I have two 1992 2.5L 200hp in my garage compression is even on both engines right at 110psi.

[flyingfrizzle]

More even the better, A lot of the latter 2.5s should have 120-130 per cylinder and you want all of them with in 10%. The 1992 year compression could be a little lower than the latter years 2.5s but 110 is not bad if even. Seems like the 1991 year had a ton of changes or variances but the 1992 model should be more standard. Never the less if you are with in 5 psi of each hole I would be happy. A leak down test will give you a little better idea of what the bores look like but the 2.5s live forever if taken care of.