I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So… what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre

A stuck carb float or choke would be my guess. This will cause the carb to
run rich and flood. May or may not ever happen again.
I would remove the carb and tear it down and clean good. If you can't do
yourself have it rebuilt as a safety precaution.

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com

-
"Melandre" wrote in message
...
I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So. what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre

I concur on the stuck float which could also be some crud holding the needle
valve open that cleared itself, and hopefully won't happen again. In the
meantime, you might do some reading up on your particular carb, and maybe
pick up a needle valve/float kit and replace (should only be a coupla
bucks). I had a similar (occasional) problem with my 4bbl last season. I
installed a fuel line shut off and ran the carb dry before storing for the
winter assuming that maybe this year I'll be replacing the needle
valve/float. This spring I topped up the carb through the vent with cleaner
and let it sit for a while, then turned on the gas and started it up (all in
the laneway using the muffs/garden hose). For what it's worth, no problems
so far.

I have read that shutting off the gas if the float sticks, running the carb
dry, then tapping the carb *gently" with a hammer might free a stuck float
(dunno if that would apply with an electric fuel pump) ... but hey, if it
gets you home :-).

Thanks for your quick help.

Is the choke the little flappy thing (obviously don't know the proper
term) on top of the carb? When I stopped the boat and removed the
flame arrestor, I noticed that the "flap" was wide open (this is how I
could see the gas bubbling inside). Again, I know very little about
this stuff but isn't this flap supposed to be closed when the car/boat
is not running???? Is it always open when the boat is running? This
may have been the stuck part maybe (which I probably loosen back by
simply touching it)???

Andre
PS: Sure thing about having it looked over by someone knowledgeable
(this excludes me!). I don't want to go boating in fear all summer...




On Tue, 21 Jun 2005 01:30:41 GMT, "tony thomas"
wrote:

A stuck carb float or choke would be my guess. This will cause the carb to
run rich and flood. May or may not ever happen again.
I would remove the carb and tear it down and clean good. If you can't do
yourself have it rebuilt as a safety precaution.

Here is a scenario that might have happened to your boat.
Boat carburetors are designed to vent overflowing gas into their throats.
You may have observed some gas percolating in the intake manifold resulting
from an overheated engine. The overheat may have resulted from a plastic bag
being sucked against the water pickup in the lower unit. When you shut the
engine off the bag drifts away and no more overheating.
JIMinFL

"Melandre" wrote in message
...
I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So. what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre

The flap on top is the choke. It should be closed partially when the engine
is cold but once it warms up it should be open. Since you indicate that it
was open then this is probably not the problem.
Chances are the float stuck w/ the needle open and allowed the fuel to
overflow the bowl and up into the throat of the carb.
Usually vibration will unstick it. Chances are when you took the flame
arrestor off you bumped it enough to unstick the float and it started
working.
Once it sets for a week it may stick again.
I would have the carb rebuilt/cleaned before continue to use to ensure a
safe situation.

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com

-
"Melandre" wrote in message
...
Thanks for your quick help.

Is the choke the little flappy thing (obviously don't know the proper
term) on top of the carb? When I stopped the boat and removed the
flame arrestor, I noticed that the "flap" was wide open (this is how I
could see the gas bubbling inside). Again, I know very little about
this stuff but isn't this flap supposed to be closed when the car/boat
is not running???? Is it always open when the boat is running? This
may have been the stuck part maybe (which I probably loosen back by
simply touching it)???

Andre
PS: Sure thing about having it looked over by someone knowledgeable
(this excludes me!). I don't want to go boating in fear all summer...




On Tue, 21 Jun 2005 01:30:41 GMT, "tony thomas"
wrote:

A stuck carb float or choke would be my guess. This will cause the carb
to
run rich and flood. May or may not ever happen again.
I would remove the carb and tear it down and clean good. If you can't do
yourself have it rebuilt as a safety precaution.

In article ,
says...
I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So? what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre




If it had been a fuel leak it is unlikely you would see smoke and the
odor of gasoline would have been immediately apparent.

Smoke from an engine is the usual result of some sort of oil spill on a
hot surface. Power steering oil possibly? Check the levels of all your
engine fluids and keep an eye on them.

--
Mike G.
Heirloom Woods

www.heirloom-woods.net

Andre,

You've had several good recommendations. It seems that you are not terribly
mechanically inclined. So, I don't recommend you attempt to remove,
disassemble, repair the carb, etc.

I'd get a can or so of carb cleaner and add it to the fuel tank then just
use the boat as usual.

Did you add fuel stabiliser to the tank at the end of the season last fall?
If not, be sure to add some at the end of this boating season. Take the
boat for a good long run... 20 minutes or so after adding the stabiliser to
ensure the treated fuel reaches the carburetor and fills the float chamber.

If the carburetor cleaner treatment fails to do the job have the problem
taken care of by a professional.

Good luck.

Butch
"Mike G" wrote in message
ews.com...
In article ,
says...
I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So? what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre

On Tue, 21 Jun 2005 02:36:44 GMT, "JIMinFL" wrote:

Here is a scenario that might have happened to your boat.
Boat carburetors are designed to vent overflowing gas into their throats.
You may have observed some gas percolating in the intake manifold resulting
from an overheated engine. The overheat may have resulted from a plastic bag
being sucked against the water pickup in the lower unit. When you shut the
engine off the bag drifts away and no more overheating.
JIMinFL

"Melandre" wrote in message
.. .
I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So. what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre



This sounds reasonable. Check the rubber portions of the exhaust. If water
stopped going thru the exhaust, these may have gotten hot enough to start
smoldering. They put off a *lot* of smoke when they do. (Experience speaking
here!)
--
John H

"All decisions are the result of binary thinking."

Good advice. I suggest you consider going one step further, if you havea
friend that is handy get him just to look over the engine to see if he has
any observations. Or I'd even consider paying a half hour or so of labor at
the local marina to let one of their guys take a look at it.

"Butch Davis" wrote in message
ink.net...
Andre,

You've had several good recommendations. It seems that you are not
terribly mechanically inclined. So, I don't recommend you attempt to
remove, disassemble, repair the carb, etc.

I'd get a can or so of carb cleaner and add it to the fuel tank then just
use the boat as usual.

Did you add fuel stabiliser to the tank at the end of the season last
fall? If not, be sure to add some at the end of this boating season. Take
the boat for a good long run... 20 minutes or so after adding the
stabiliser to ensure the treated fuel reaches the carburetor and fills the
float chamber.

If the carburetor cleaner treatment fails to do the job have the problem
taken care of by a professional.

Good luck.

Butch
"Mike G" wrote in message
ews.com...
In article ,
says...
I do a 20 minute boat run between the marina and my small cabin almost
every weekends. Something weird (and a bit scary) happened last
weekend. I warmed up the boat (idle) for about 5 minutes while
loading it and then we stated our usual run to the cabin. After about
5 minutes, my wife noticed a burnt smell and sure enough, when we
looked at the engine compartment, lots of smoke was coming out of it.
I have an older 18' Bayliner (1990) with an I/O OMC Cobra 2.3L
twin-cam engine. Because it is an I/O, I couldn't quite see inside
but my first reaction was that I may have a fire going in the engine
compartment (probably did!) . I promptly stopped and shut off the
boat and opened the engine compartment.

While I could not see an obvious fire, I suspected that gas overflowed
from the carb and spilled on the engine (would that be enough to
create all the smoke?). I unscrewed the flame arrestor (which was
very hot when normally it is not) and sure enough I could see gas (I
think) bubbling inside the carb (could a fire starts there???).

We were looking at a long paddle back to the marina and not knowing
much about boat mechanic (and therefore not having a clue what the
problem might be), I was a bit wary about even restarting the boat
(not wanting an explosion, a fire or blowing the engine). However,
the bubbling gas eventually dissipated so after 5-10 minutes, I
decided to give it a go (without the arrestor in place so I could
observe in there). The boat started and we started heading back
slowly toward the marina. Once I got in front of the marina,
everything looked OK (no more overflowing gas or burning smoke) so I
opened the throttle a little to do more testing. Everything OK again.
Put the flame arrestor back on and more testing. Again everything OK
and the flame arrestor was cool to the touch. After sufficient
testing, I concluded that things appeared to be back to normal, and
with the engine cover still off (so I could stop at any sign of
trouble), we turned around and proceeded to the cabin. 20 minutes
later we arrived at our cabin and again I checked around, touch the
flame arrestor and everything appeared normal. Use the boat a bit at
the cabin and again OK. Came back from the cabin last night to the
marina and no problem.

Otherwise the boat runs smoothly, no weird noise or other noticeable
problems.

So? what the heck happened! Even though the problem dissapeared as
quickly as it appeared, I am a bit freaked out that it will happen
again with perhaps more dire consequences next time. Any
suggestions, recommendations, advises or comments would be most
welcome.

Andre