Holley 4160 leak…

[Georgiasquare]

I have a leak on my Holley 4160 after a rebuild. I did a complete rebuild and replaced every gasket cleaned with a soak, carb cleaner, and compressed air. The rebuild came after I let the truck sit for a few months.

I noticed the leak after installing the carb post rebuild and it would not start. I jammed the throttled blades open with a screw driver to look down the throat of the carb and did not see any few leaking from the venturis. When I actuated the the accelerator pump lever by hand no fuel came out of the nozzle however it is coming from somewhere below the nozzle I just cannot see where because the choke is in the way. After pumping the lever a few times I can get the fuel to come from the nozzle almost like the channel has to prime itself.

Any help/guidance would be greatly appreciated.

If there are any questions I will answer them as best as I can.

 

[nvrenuf]

You never said where it’s leaking from. Are you seeing a leak or are you assuming there’s an internal leak because you’re not getting fuel?

It sounds more like an internal blockage than a leak.

Are you sure you have good fuel pressure at the carb?

 

[Georgiasquare]

So I cannot see exactly where the fuel is coming from as the choke plate blocks my few but I can see the fuel entering the throat of the carb mainly on the primary passenger side. It is pooling in the intake. I pinned the throttle blades open to look down the throat of the carb and could not see the source of the leak however, it only leaks when I manually push down the accelerator pump lever. If I pumped it rapidly for a few seconds I can get a weak shot from the accelerator pump nozzle. My fuel pressure is a bit low at 4.5 PSI but I wouldn’t assume that to cause this issue.

 

[goldpack]

while looking at other things:

you can put some dye in the fuel to help locate anything that is hard to see...
(gasoline likes to make vapor easy,...but the dye will show where it is coming out).
I use very little of this less than the directions,...so I have had the same jug on my shelf for 20 years. (similar to the stuff for HVAC coolant...but for petroleum)

https://amzn.to/3U27GH4

(....and if you put some in the tanks you might see something else rusted / brittle glowing lime green on a 40 year old antique).