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1992 5.0 HO carb issue

D

Dekle5

New member
Boat cranks and runs fine for about 15 minutes on motor flusher. After turning off and trying to crank I have to really choke it and when I pull back to idle it dies. 2 barrel Holley carb. New water separator, fresh gas, checked screen in carb, all clean. Mechanical fuel pump checked out fine. Please help. No one in my area works on OMC.
 
A Holley carb is a Holley carb no matter if it's on an OMC or a Volvo, or a Chevrolet or a Ford for that matter!
Sounds like you need choke to keep it running after it warms up, that suggests that the carb's idle passages are clogged and it needs more fuel to keep running than it should.
A Holley 2bbl is very simple to clean and rebuild, there are vids all over You Tube on this...
 
If it idles for 15 minutes, sounds like the idle circuit is functional..

When you say " I have to really choke it"...what are you doing ?? That vintage should have an automatic choke...hence the question...
 
makomark said:
If it idles for 15 minutes, sounds like the idle circuit is functional..

When you say " I have to really choke it"...what are you doing ?? That vintage should have an automatic choke...hence
louc said:
A Holley carb is a Holley carb no matter if it's on an OMC or a Volvo, or a Chevrolet or a Ford for that matter!
Sounds like you need choke to keep it running after it warms up, that suggests that the carb's idle passages are clogged and it needs more fuel to keep running than it should.
A Holley 2bbl is very simple to clean and rebuild, there are vids all over You Tube on this...
Click to expand...
it’s a new remanufactured carb from Guaranteed Carburetors out of Florida. Put it on this past weekend and ran fine for 15 minutes. Turned off and tried to crank and that’s when it wouldn’t crank unless I depressed the button on the throttle and gave it gas. Yes it has an automatic choke but it would not crank. This was the same problem my sons were having with the boat before they joined the Marines. Maybe the carb wasn’t the issue to begin with. Father in law suggested replacing the carb. Any ideas what to look at next?
Click to expand...
This
 
First item - seriously, I'd suggest researching the different words used to describe engine operations and activities...ie opening the throttle never equates to a choke operation...will not crank = the engine's crankshaft won't spin when activating the starter..

second item - make the adjustments to the new carb per the rebuilder's directions (or the factory service data).

third item - make sure the automatic choke opens fully once the engine warms up.

fourth item - thank the father-in-law's advice but don't act on it...
 
Agreed, we need to know what it's doing, in understandable terms
Cranking is engine spinning over to try to start
Firing up means it's starting
Choking meant giving it more choke than usually expected/needed.

I think it would be good to verify proper auto choke function first.
Cold engine with throttle opened up for starting (about 1/4 open) choke valve should fully or nearly fully close
Engine starts, choke unloader should pull the choke plate open about 1/8th" to give it enough air to keep running
Note, marine auto chokes do not have fast idle cams like automotive carbs, to keep it running, while warming up you have to set fast idle manually with the throttle lever.
Next the electric choke should open fully in about 5 min of running, if not the heating unit is not getting constant voltage
If that's the case the engine will not run right because it will be running much too rich. On these electric auto chokes, the default position is closed, it needs a constant voltage source and ground, to stay open.
 
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