Nancy wrote:

"Gould 0738" wrote in message
...
It does sound like fuel & it seems when your tank level is down a
bit???
So
empty the tank & make sure the line from it to the lift pump is OK;


Hmm. It sounds like fuel until you take into account that both engines are
drawing from the same tank. Helps rule out contamination. If the lift pump
was
weak, wouldn't it be difficult to sustain adequate fuel flow for the high
RPM
operation Nancy is able to achieve when the engine is cold? My horseback
guess
is the fact that the engine will run OK again after a complete shut down
of
15-20 minutes may be significant.

We did shut down completly for about 10-15 minutes to refuel yesterday on
the way back in. The engine did the same thing..but we only put about 20
gallons of gas in the tank at that time, so it may not have been enough.
When you say 'lift pump' what is that? Where is it? I'm not familiar with
that. Fuel pump?

Yes the fuel pump.

I had someone suggest that with the fuel tank fairly
full, it the fuel pump does not need to pump as 'hard' (due to gravity and
weight from the fuel I'd presume) so is able to sustain adequate operation,
but when the tank gets lower, the pump has to actually work harder? I ran
this by someone else, who said that if there were a tear in the fuel pump
there would be fuel leaking into the engine oil. This is all fairly well
beyond my knowledge base, so I'm just trying to come up with ideas of places
to check here.

That's true but if there is any sort of fuel restriction once the fuel in
the tank is lower it will be aggravated. i.e. a fitting that is fine when the
tank is full, might leak air when the tank is lower.




Don't overlook the possiblity of an ignition part that gets screwy at a
certain
temperature and works OK again when it cools down. Once had a cracked
distributor cap on a gas engine that acted like this. After running long
enough
for the cap to respond to heat- it would run like crap. After sitting long
enough for the cap to cool back down again- it would run fine for a while.

Hmmmm, wouldn't it reach a sufficient heat range much sooner than after
several hours of running though? The engines do not run hot at all really.

Yes again true but as Chuck says don't overlook anything, many ignition
problems only become manifest when the engine is hot.




But, again, that's a wild guess by a guy who boats with a proper diesel
and
doesn't have to mess with an ignition system. :-)

hehehe, I wish I could afford to put a couple of diesel engines in this
boat. Would be a bit spendy though, no doubt.

Thanks for the responses so far everyone. They're appreciated and will give
me places to begin looking next.

Nancy