help with 2 bbl issue

Cudamank

Member
Carb is on a 345 and is a Holley 2bbl. Side hung float, will have to get the carb list number when back to the house. I rebuilt the carb with a napa carb kit. Truck idles fine. However, when given 1/4 throttle or more, fuel siphons out of the vent tube and into the carb. I have check the float level with the plug on the side of the carb and it is set to just below the threads.

Any ideas?
 
Did you put the main jets back in it? They would be the little brass slotted buttons that are near the bottom of the metering plate. That or the power valve could be stuck open.
 
Couple of more questions. The vent tube sticks up out of the front of the carb. The boosters are the round structures on a stalk in the center of each venturi. Fuel can't siphon out of the vent, it will only overflow. It can appear to siphon from the boosters which is where it is supposed to come out at mid to full throttle.

So exactly where is the fuel coming from? Also one other thing to check, specially with a 3rd party kit is that all the passages match the original gasket, if you still have them.
 
The fuel is coming up from the vent tube that comes off the carb body. Its not from the bowl being too full, but like coming up and then being drawn into the top of the carb. Will have to take a video or picture of it. Daughters 11th birthday party took up the weekend.
 
Are you using the stock fuel pump? Fuel pressure going high and over coming the float needle seat pressure is the only thing I can think of that would cause that.
 
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