Butch,

ALl the parts up until the new rebuild carb were done and diagnosed by
a qualified mechanic.. (the mechanic did rebuild my orig. carb the
first time)

I'm thinking about taking it to a different mechanic at this point..
although I might try to look at the anti-siphoning valve, and then also
unhook the fuel hose from the fuel tank and put it in like a 5 gallon
tank of gas and see if that works.. i think that would tell me a lot,
whether or not it is something BEFORE the fuel filter.. the mechanic
never really even did any testing on what came before the fuel filter..


Butch Davis wrote:
Kyle,

Geez, you've spent a heck of a lot of $$$ replaceing parts not known to be
defective. This is because you have no troubleshooting skills. The good
advice you've been getting from the group is based upon what you're saying,
but it's very difficult to trouble shoot an engine via the written word.

IMO, you'd have been way ahead to have taken your boat to a qualified
Mercruiser mechanic. If, after all the time and money you've invested so
far you've still not cured the problem, I recommend a qualified mecanic.

Good luck.

Butch
"sherwindu" wrote in message
...
Make sure your filter is fine enough. For outboards, they recommend 10
micron.
You may have water in your fuel, especially if your using gasahol. Try a
filter
with
a water seperator. Try replacing all your fuel lines if they are old.
Give
your tank
a good inspection and cleaning, as well. You might also try a product
called
Quick
Clean from Mercury in your gas to keep the carbs clean. Let us know if
you fix
it
and what the solution turned out to be.

Sherwin D.

kyle wrote:

hi all,

i am at my wits end over this 2003 bayliner 5.0L merc.

here is the symptom:

give it some warmpup throttle action, turn key on, she cranks
beautifully. no smoke. no roughness.

10-20 seconds later, she instantly cuts off.

so.. youre thinking.. it must be a fuel thing, right?

i started small: i replaced the fuel filter. same result.

a little larger: i replaced the fuel pump (it's an electronic fuel
pump, we tested with it unhooked from carb and it was a weak stream..
after replacement she was peein' strong). same result.

a little larger: i replaced the ignition coil. same result.

a little larger: i rebuilt the carb. at this point, she showed
promise. we took her out on the lake for about an hour and she ran
beautifully!! i let her sit for a week .. then bam, same damn result
as before!! 10-20 second purr then cut off.

so i said damn it, let's look at the carb again. no fuel is getting
down in the manifold after the initial warmup throttle action!! so
figured something is messed up with carb.. went down and bought a fresh
rebuilt carb.. last night.. put it on.. same result! and i still
don't see fuel dropping into the 2 barrels after crankup. it does
make a noise like it's spraying air or something at least. but it was
somewhat dark when i was observing it this time...

the guy i bought the boat from had done a lot of wiring himself (mp3
player, gps..) .. could it be some electrical shorting after 10-20
seconds or would it only be a startup thing?

my next order of business is going at it from the distributor system.
maybe the distributor chip is bad? distributor cap? what else could it
be!! man this is driving me nuts. that engine is practically new at
this point!!

also, what do you think about some crap in the fuel? i filled the damn
tank up from about 3 gallons.. but what if there is dirt or water or
something in the tank and it keeps suckin' up dirt? should i drain the
40 gallon tank.. and clean the tank somehow (never done that.. whats
the best way to do it?) give that a shot? the one thing that leads me
to believe it isnt the tank is that when i warmup throttle action it
pushes fuel down the manifold so the fuel filter seems to be fine?
maybe just not fine all the time?

any suggestions would be great. i've had it in and out of the shop and
they had it fixed at one point but then 1 week later it died again
(without me doing anything in between then).

i'm tempted to sell the boat, get something else, but i am in it $12K
and who is going to buy an '03 bayliner 21.5ft that doesnt run for
anywhere near that?? best bet is to get it running, then sell it, i
guess, or maybe keep it since ive grown attached :

thank you so much for your time reading this,

kyle