timW brought forth on stone tablets:
Hi there,
I need a bit of advice on an issue we're having starting
our boat up.

We purchased a 95 Sea Ray Sundancer a few months ago that came with a
two year old 5.0 Mercruiser and recently replaced manifolds. All went
reasonably well on the first couple of trips out but the last time we
tried taking it out for the day I couldn't get the thing to start. I
tested it out the previous day at our home and had the same issue,
though I did manage to finally get it cranked up and running.

On each occasion the same thing has happened. I give the engine a
couple of pumps with the throttle, as instructed by the previous
owner, leave the throttle slightly open, and turn the ignition. After
a couple of tries it starts and all seems well, until I throttle it
back to idle. The engine ticks over for maybe 10 - 20 seconds, then
begins to sound progressively rougher until it cuts out altogether.
After that I can't get it running at all. The first time, on the
trailer at home (yes, I did have water running to it) I managed to
coax it to life half an hour later, and kept it revving for a while
before I set it back to idle. But when we went to launch the boat on
the weekend, the damn thing cut out on me at idle and refused to start
up again, even after we let it sit at the dock for half an hour,
trying over and over. I virtually drained the batteries in my
attempts.

A neighbor, who's a pro fisherman, is of the opinion that it may be
something as simple as a fuel filter being clogged. This might gel
with our first couple of trips out, when the engine kept cutting out
on us at higher speeds.

Any views on the matter? And if it is the fuel filter, can someone
tell me where to find it on the engine - yep, I'm about as
mechanically inept as they come, but am willing to learn for the sake
of the boat!

Thanks in advance............Tim


Tim -

I assume that this is a gas engine.

If carbureted:
o Over zealous choke - staying on too long and flooding the engine
o Not likely to be an under-achieving choke. If it were, the
engine would quit lean, and then your normal startup procedure would get
you a restart (which would then fail, in the same way). This is
not what you described.
o Unlikely to be the fuel filter - if the fuel filter was so
blocked that the engine wouldn't idle, you'd never get it to run above idle
o Failed needle valve in the carb - allowing the float tank to
overfill/overflow and flood the engine
o Sunken float - the result is the same: the float tank over fills
and floods
o If the engine runs normally once it is warmed up, I don't suspect
anything electrical

If fuel injected:
o Bad sensor
o Bad connector (yup, there's a lot of 'em...)

Have you made any changes to the engine? If so, these should be the
FIRST thing you check



Note Note *NOTE*:
Be very careful. A gas leak in a boat is NOT the same as in a car. In
a car, it just runs onto the road, and the entire engine compartment is
very well ventilated by the open bottom, and the radiator fan. On a
boat, the fuel runs into the bilge, where the vapors accumulate. You
could BLOW UP THE BOAT. If you smell gas (fuel leak, carb overflowing,
etc), stop what you are doing and walk away. DO NOT operate any
switches (even turning off a switch makes a spark...). And of course,
you have your ventilator fan running, right?

bob
s/v Eolian
Seattle