Blue/Black Smoke when starting...
 

I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat up
on the weekend after not starting up all week i get a blue/black smoke for
about 20 seconds then it dissapates. Also when starting it for the first
time i need to pop it in neutral and rev the rpms or else it will stall.
Any suggestions? ? ? Some have said since its an older boat/engine that is
nothign to worry about. Once it's running the smoke goes away and after
running a while i can start it right up w/o reving the rpms. Any info is
appreciated ;)

-matt

Start checking to see if the oil level drops. You may have some worn valve
stem seals or have worn rings. A cylinder leak down test would be a good
thing to have done. My old GM S10 smokes on startup for about the same time
and I'm not worried. Stalling maybe be a choke or carb issue.



"ToneJohn" wrote in message
...
I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat up
on the weekend after not starting up all week i get a blue/black smoke for
about 20 seconds then it dissapates. Also when starting it for the first
time i need to pop it in neutral and rev the rpms or else it will stall.
Any suggestions? ? ? Some have said since its an older boat/engine that is
nothign to worry about. Once it's running the smoke goes away and after
running a while i can start it right up w/o reving the rpms. Any info is
appreciated ;)

-matt

Yeah.. mine will stall only if i don't give it some juice but after about
1-2 minute of running initially it starts up w/o any problems and runs
perfect.......


"Woodchuck" wrote in message
.. .
Start checking to see if the oil level drops. You may have some worn valve
stem seals or have worn rings. A cylinder leak down test would be a good
thing to have done. My old GM S10 smokes on startup for about the same
time and I'm not worried. Stalling maybe be a choke or carb issue.



"ToneJohn" wrote in message
...
I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat
up on the weekend after not starting up all week i get a blue/black smoke
for about 20 seconds then it dissapates. Also when starting it for the
first time i need to pop it in neutral and rev the rpms or else it will
stall. Any suggestions? ? ? Some have said since its an older boat/engine
that is nothign to worry about. Once it's running the smoke goes away and
after running a while i can start it right up w/o reving the rpms. Any
info is appreciated ;)

-matt

I guess it's carburated? With my '83, after a week of sitting, it's a)
necessary to "pump" it once or twice to squirt some fuel into it (4 bbl
QJet) and b) necessary to leave the throttle open a bit for a minute or two
because I'm too lazy to set up the fast idle :-)

The smoke may simply be the result of the choke being on ... and maybe
that's why you need to keep the revs up a bit at first..

"ToneJohn" wrote in message
...
I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat
up
on the weekend after not starting up all week i get a blue/black smoke for
about 20 seconds then it dissapates. Also when starting it for the first
time i need to pop it in neutral and rev the rpms or else it will stall.
Any suggestions? ? ? Some have said since its an older boat/engine that is
nothign to worry about. Once it's running the smoke goes away and after
running a while i can start it right up w/o reving the rpms. Any info is
appreciated ;)

-matt

In article ,
says...
I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat up
on the weekend after not starting up all week i get a blue/black smoke for
about 20 seconds then it dissapates. Also when starting it for the first
time i need to pop it in neutral and rev the rpms or else it will stall.
Any suggestions? ? ? Some have said since its an older boat/engine that is
nothign to worry about. Once it's running the smoke goes away and after
running a while i can start it right up w/o reving the rpms. Any info is
appreciated ;)

-matt





If it were my F250 the first place I'd be looking is at the carburetor.

--
Mike G.
Heirloom Woods

www.heirloom-woods.net

The blue smoke is from a leaking valve guide that allows oil to slowly run
into the cylinder after it sets for a while. Keep a watch on your oil. Not
worth fooling with until it starts to smoke all the time.

Rev the engine when cold is normal. Your choke may be out of adjustment
slightly but unless you can adjust it yourself not worth the money to take
to a repair shop.

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

-
"ToneJohn" wrote in message
...
I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat up
on the weekend after not starting up all week i get a blue/black smoke for
about 20 seconds then it dissapates. Also when starting it for the first
time i need to pop it in neutral and rev the rpms or else it will stall.
Any suggestions? ? ? Some have said since its an older boat/engine that is
nothign to worry about. Once it's running the smoke goes away and after
running a while i can start it right up w/o reving the rpms. Any info is
appreciated ;)

-matt

In article , says...

I have a 94' Chaparral with a 5.7 V8 Mercruiser. When starting the boat up
on the weekend after not starting up all week i get a blue/black smoke for
about 20 seconds then it dissapates. Also when starting it for the first
time i need to pop it in neutral and rev the rpms or else it will stall.
Any suggestions? ? ? Some have said since its an older boat/engine that is
nothign to worry about. Once it's running the smoke goes away and after
running a while i can start it right up w/o reving the rpms. Any info is
appreciated ;)

-matt



This one is easy. The fuel in the carb is perculating down into the intake
manifold and into the cylinders who's valves happen to be open at rest. This
gas washes the oil off the cylinder walls. Presto!!! Next time you start it
up after having sat for several days, you get black smoke from the excess
fuel, and blue smoke from the oil which was fluidized off the cylinder walls.

This is common when the needle valves associated with the carb floats
allow fuel to seep past when the engine is shut down. When you turn the
engine off there is residual fuel pressure in the line, and sometimes
that excess fule ends up in the carb, and spills over into the intake
as described above.

Solution, have the carb rebuilt, or just live with it. Gas washing of
the cylinders will reduce the overall life of the engine, but I think it
would be hard to measure how little.