"Carl Fredrik" wrote in message
...
Hi everyone,

I've tried for hours to find the correct cylinder compression for my
Mercruiser 3.0L -88, but I just can't seem to find it anywhere. I saw
similar engines rated at 130 PSI from the factory, but if anyone could
give me an authoritative answer on this particular engine, I would be
very grateful.

I just did a compression check on my engine, and get the following
results: 120, 120, 120, 180 PSI. I have little experience with this,
so I would appreciate any advice or comments on how to remedy this
situation.

Sincerely,

Carl, Sweden

The 180 is abnormal. May be some water in that cylinder. What ever, that
is the problem cylinder.