Flooding problem on a Holley 4150 carb

[John C.]

I am having problems with gas flooding on my Holley 4150 carb. With the engine running and immediately after shut off I get a constant flow of gas through the secondary jets. I thought it was a float problem, so I removed the secondary bowl and checked the float, float level, and needle valve. Everything seems OK yet the problem continues.

Any ideas on what else I should be looking at to correct this?

John

[Clem Z.]

Re: Flooding problem on a Holley 4150 carb

make sure the bowl vent is not plugged. if the secondary float is a nitrophyl check it for weight,about 15 grams is correct. with the bowl off of the carb set it upside down and check for leak thru using 8/9# of air pressure in the fuel fitting using some water soap solution inside the float bowl

[Mark B.]

Re: Flooding problem on a Holley 4150 carb

John, when setting the floats on a 4150 Holley, you must have the engine running at idle. Take out the side screw from the bowl, loosen the screw on the top of the inlet/needle assembly and use the nut to back off the assembly until just a dribble comes out of the hole. I always set my secondaries lean, meaning that there would be no dribble out of the hole on the secondary side. The front float bowl is set the same way with a dribble. Checking the flotation of the floats is always a good idea even if they're brass. Small pinholes can develop causing the floats to take on fuel disturbing their bouyancy. Nitrophil floats are usually black in color and look like foam. Recent gasoline formulations can affect their ability to float properly.