Holley carb leak

Simon · 04-04-05, 04:09 AM

After re-installing my radiator and battery yesterday, I thought I'd try and start my car. I turned on the ignition and fuel pump and then noticed some fuel leaking from the float adjuster on the top of the carb (Holley 650cfm DP)
before I start stripping it down, what would cause fuel to do this?
The car has been sat since my accident last july, would the float be stuck and not shutting off the fuel flow?
Any advice greatly appreciated.
Thanks

Simon

Simon · 04-04-05, 05:35 AM

DON'T PANIC !!

Tried it a short while ago and it's fine. I guess the float may have been stuck.
Thanks
Simon

Howard Jones · 04-04-05, 12:21 PM

Simon, fuel should not leak from the float adjustment setscrew. There is a thin round seal under the screw. It may have dried out. Or it , the screw, may be loose. You should make this right. A fuel leak here will deliver fuel right on top of the motor where all the heat is, near headers, and you will get a lot of vapor fairly quickly.

The stuck float needle was the cause of excesive fuel flow but the seal on the float adjustment screw was the cause of the leak. Usually a stuck needle allows a lot of fuel to flow into the carb and down into the intake manifold. This causes the motor to run very rich. But no external leaks.

You just fixed the front and I would hate to see pictures of your car after the fire.

Mike Dozier · 04-04-05, 01:56 PM

There are two paper gaskets...one under the washer and one
above....renew both...not hard to replace them without disturbing float setting.

The brass indicator plugs on the side of the bowls also have
paper gaskets...suggest replacing with clear plastic
(see through) plugs available from usual mail order stores.

MikeD

Howard Jones · 04-04-05, 08:15 PM

Some blends of gas, ours here in Northern Calif. USA for one, will cause the plastic plugs to seize. Pain in the ass to get them out then. I would recomend you leave the brass ones in.

StanJ · 04-09-05, 10:54 PM

We've seen these clear plastic "sight plugs" swell and seize on several occasions as well when used on "pump gas" street cars. Decent concept....wrong material. As an aside, we won't use them in racing carbs for product liability reasons; in the event of even a reletively minor engine compartment fire resulting from a wreck, these plastic plugs can burn away pretty quickly...allowing the fuel remaining in the float bowls to turn a small problem into a much large one.