Compression numbers... what to do?
 

Hello-
I recently purchased a used boat - 2002 with only 35 hrs on it.
The compression numbers:
#1 130
#2 185
#3 180
#4 185
#5 180
#6 180

The mechanic who looked at it said that with so few hours on the boat,
its obvious that its sat for a while and that after use - the
compression in #1 would go up.
Should I be concerned? If so, what are the likely reasons for the low
compression in #1?
Fyi... its a Mercruiser 4.3

Thanks!

On 21 Apr 2005 11:05:06 -0700, "JaxDawg"
wrote:

Hello-
I recently purchased a used boat - 2002 with only 35 hrs on it.
The compression numbers:
#1 130
#2 185
#3 180
#4 185
#5 180
#6 180

The mechanic who looked at it said that with so few hours on the boat,
its obvious that its sat for a while and that after use - the
compression in #1 would go up.
Should I be concerned? If so, what are the likely reasons for the low
compression in #1?
Fyi... its a Mercruiser 4.3

Run it for a couple of hours, then retest.

It could be any number of things - dry cylinder, valve sticking,
things like that.

It's not anything to worry about at the moment. Like I said, just run
it for an hour or two at varying speeds and check it again.

Later,

Tom

"JaxDawg" wrote in message oups.com...
Hello-
I recently purchased a used boat - 2002 with only 35 hrs on it.
The compression numbers:
#1 130
#2 185
#3 180
#4 185
#5 180
#6 180

The mechanic who looked at it said that with so few hours on the boat,
its obvious that its sat for a while and that after use - the
compression in #1 would go up.
Should I be concerned? If so, what are the likely reasons for the low
compression in #1?
Fyi... its a Mercruiser 4.3

Thanks!


Add a few ounces of motor oil into the spark plug hole in the #1 cylinder
do a comp check immediately. If it the comp goes up close to the other
cylinders it's rings. If it does not go up or barely goes up it's more likely
a valve problem. Sometimes a valve can stick upon extended sitting or a
valve might crack or burn and not seat properly if it was defective from
the factory. Valve stems can even get bent.

CN