The two bolts holding the starter to the block actually snapped. There are
no traces of rust on either bolt. The hole to outer most edge of the block
actually had a chunk of the block come off with it, that has to be welded
back on. I do have some experience with older car engines and understand the
basics of dieseling. The boat mechanic mentioned hydrolock, but at the time
the engine wasn't locked. I carry a small tool kit onboard was able to turn
the engine via all of the belt pulleys a full revolution with a small
ratchet wrench. Idle speed per the tach was about 750-800 rpm. As far as
the gas, I've only used Citgo 89 octane, all from the same station right
near where I launch. The owners manual does specify a minimum of 89 octane.
After the engine shut down, even after dieseling, I never had any problem
starting it, and it didn't diesel every time it shut down which if it was
bad gas I assume it would. I do think the are trying to place the blame on
the gas which would make it a non warranty issue. I also know once this is
resolved I will find another Volvo/Penta repair facility to take it to

"Rod McInnis" wrote in message
...

"John" wrote in message
. com...
Its in the shop right
now because the starter basically blew off the block a few weeks ago.

I am having a hard time picturing what happened. The starter ripped off
the engine?


The
mechanics are telling me there are traces of water in the cylinders and
that
is what is causing the problem.

Water in the cylinders would certainly make the starter work extra hard to
overcome the added compression. Too much water and the engine "hydrolocks"
and it can't be turned over at all. I would expect such a problem to
cause
the starter to burn out or struggle, not "blow off the block". If the
starter came loose, then the bolts weren't tight enough!

. Apparently when an engine diesels the pistons go in reverse which
sucks water in through the exhaust riser (not covered by the warranty).

That is a common form of "dieseling". It is also possible that engine
continues to "diesel" in the normal rotation. A reverse direction of
dieseling is very short duration as it can't continue to get a supply of
gasoline to keep it going.
If it does run backwards, however, it will definately suck water back up
the
exhaust. This is very, very bad! Cold water hitting hot exhaust valves
and
pistons can cause things to crack. Water left in the cylinders will make
it
harder (maybe even impossible) to start the next time.


When
I asked what cause the dieseling, they said probably bad gas (water in
the
gas).

Not water in the gas. Too low of an ocatne gas yes. Check the owners
manual on the engine and see what octane rating it requires. I wouldn't
expect a 4.3 L to require high octane gas, but I could be surprised.

Talking to a car mechanic, he said the primary causes of dieseling are
incorrect timing, of the carburetor being set too rich or lean.

Not too rich, but too lean for sure. I would be surprised, however, if
your
carburetor had an adjustment for the main jet mixture.

An engine diesels because the temperature inside the cylinder is too hot.
You can have this condition even if the engine isn't overheating. The
timing being off is a good possibility. Another possibility is that a
vacuum
leak is causing the mixture to lean out.

This hit me
funny because this same dealership did a 50 hour tune up on the boat in
November. I have maybe 20 - 40 hours on it since the tune up.


Well, it may be too late now, but I would have taken the boat back to the
dealer the first time it dieseled and make them fix it! To have an engine
diesel after a tune up means that they did something wrong! If your
dealer
is trying to duck the issue and blame other things then I would find a new
dealer!

They could argue that water in the cylinders isn't covered, but I would
argue back that the water got their because they screwed up the engine and
caused it to diesel. Their fault.


Rod McInnis