Holley 4160 Dripping Fuel from Primary Boosters

Joined
Jul 9, 2019
Messages
19
Hi All,

Hope I got the terminology right.

Have an 89 OMC 5,0 with a Holley 4160 4 Barrel. Have been tinkering on it, had it running on muffs in the yard for quite some time on a 6 gallon outboard tank with some fuel system cleaner, new fuel filter.

Was idling great for along time (a few days on and off, also had it in the water). Then suddenly, on the hose at idle it died. Poking around I found I could get it running but it was difficult to start, and both primary boosters are dripping a lot of fuel at idle, flooding out the engine.

Pulled the carb and cleaned out the fuel bowls, power valve, and jets. Also ordered a Holley 703-29 rebuild kit but waiting on that to arrive.

Bowls looked clean and there was no crap in either of them.

When the engine stalls, the primaries continue to drop fuel for a while, so I am thinking that my needle seat has given up?

I'll be completely disassembling and rebuilding the carb when the kit arrives. Anywhere in particular I should pay close attention that may be causing this issue? Like I said, one moment she was running fine, and the next it's dumping fuel in the primaries.

Thanks!!!
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,855
Either that or there's a tiny bit of crud that got past the filer keeping it open.
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,075
Take a close look at the tiny air bleeds, if any of them get clogged up that is the usual symptom. With the idle stop screw backed out hold the throttle plate to the light to make sure that the butterflies are even and completely closed. If everything is right when you finish the rebuild the idle mixture should be 1.5 turns out and the idle stop screw 1/2 to 3/4 down after contacting the throttle lever. Any more than that and the next stage of the carburetor tries to come in with the wrong signal.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,557
Make sure all passages are clean. I push mono thru many of the passages to make sure they are clear
 
Joined
Jul 9, 2019
Messages
19
So I put on my thinking hat, and swapped the needles from front to rear since they are the same. Problem moved to the secondaries now. :) Local marina at the lake had a new needle and seat lying around, and we're back in business.

Thanks everyone!!! Hope this thread helps someone else.
 
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