holley leak

[jojoegen]

I have 2-4160's on a KC427 based 482.KC bought them new while building the engine about a year ago.Finally got the car finished and ran it.Next morning a small pool of fuel on the intake from the rear throttle shaft .Reset the floats and the next morning the same.Did this with and without engine running.Never got hot enought to percolate the fuel and of course holley warranty is over.Any ideas?

[427mudflap]

Tighten the 4 screws on the accelerator pump.

[FOMOCONUT]

Pull the carbs off tighten all screws. Jerry

[jojoegen]

Thanks friends for the come back.The leak is on the other side back barrels.No fuel around any part of the body,only from the shaft.Don't forget,the carbs are on backwards which means the front carb on a normal set up is now the rear carb.The leak is on the drivers side.Seems like the float level has gone down over night.I think.What else can it be? Johnny

[Jerry Clayton]

Check the needle/seat assy---you probably used some teflon tape somewhere and have a piece stuck in the seat holding the needle open

[Bobcat]

Typical Holley problem , but I normally see it on older carbs . The throttle shafts have "sleeve" seals and a groove about 1/8" wide machined in the shafts to accommodate the seals ( strips of a nylon material ) . The main cause of this is side load over years of operation . Replacing them can be done , but is a pain as you have to remove the butterflies and throttle shaft to do it . Specialty carb shops can also put bushings in if it really becomes a problem .
This normally only shows up when the engine is off and generally overnight . My thought is that the carbs normally operate with a low pressure across that area , so any fuel leakage goes back into the carb . It also can give you a sneak path for an air leak and drive you crazy trying to find it .

Bob

[Gaz64]

Originally Posted by Jerry Clayton

Check the needle/seat assy---you probably used some teflon tape somewhere and have a piece stuck in the seat holding the needle open

You could have something trapping a needle and seat partially open, can happen from assembling hoses etc.

Fuel leaking from the throttle shaft at rest is the booster venturis dripping from a high float level.

[Jerry Clayton]

the reason that it happens to be leaKING OUT THE THROTTLE SHAFTS IS BECAUSE ON THE 2X4S THE CARBS ARE MOUNTED BACKWARDS and that is the most rear pair of venturis---because the car runs at lower speeds on the front carb, that throttle shaft /butterflies are completely closed to make the engine idle--if it was open even a slight bit the fuel would drip into the manifold instead of leaking out the shafts. And of course the fuel comes from a defective float setting/needle/seat deal and it runs over into the venturi well area. When the car is running vacume keeps it from leaking out ( hopefully) or you are just a few trips from a fire.

Fix it and soon