My boat suffered from rough idle until warm up since the overheating
experience in early July. My marina mechanic (at the time) could not find
the problem and I lived with it up until this week when I delivered it to
the new marina we will be docking at next season. We are moving due mainly
to the outstanding reputation of their mechanics, as well as the better
overall service.

A mechanic from our new marina called me an hour ago telling me that they
suspect the problem to be caused by either a cracked exhaust manifold or a
burn out (from the overheating) of the check valves within the
manifolds............either of which would allow for water to enter the
cylinders. They will be pulling the plugs to check for water then doing a
compression check on all the cylinders to verify this and to determine what
needs to be done (possibly a winter project for them.......kaaching!!)

So, to get to my point: JohnH told me repeatedly that the rough idling
problem was connected to one of these problems and that I should find a
marina with a good mechanic.

So I am here to say............JohnH, you were right. I should have
listened to you all along. ;-)