leaking 3x2 setup

[Robert D.]

I have a 67 L71. The carbs were leaking so i rebuilt them and when i run the car im still getting fuel leakage between the front and middle carbs but only after i turn the car off and only on the right side. the problem is, i cant seem to tell where its coming from. doesnt seem to be from high up on the carbs. can it be coming from the baseplate? i tested them with a straight edge and the base plates and manifold surfaces apper to be true. is there another common place for this problem or cause ? any advice will be appreciated
thanx as always
Bob

[Timothy B.]

Re: leaking 3x2 setup

Bob,

If the heat is percolating the fuel the level will rise and leak out the nozzle onto the throttle blades then run out the side around the throttle shaft. Did you observe fuel leaking inside the venturi after hot shut down?

Also, if the metering plates are not flat fuel can leak inside the carburetor.

[Stuart F.]

Re: leaking 3x2 setup

Tim has it about right. I recently rebuilt a set for my son who had similar problems. If it is only leaking from the front carb, I would suggest you just drop the float level on that one. Remember to set it with the engine off, then run it to observe the fuel level with the plug out. If you can just see the fuel that's good enough. It doesn't have to be seeping out.

I found the end carbs specially sensitive to float level adjustment. They use a plastic foam like material for the floats, and are adjusted much lower than the center one (which has a brass float). Make sure you tighten the lock screw well on the adjuster and are using a good gasket or they will push fuel out there as well. I changed the gaskets on the end carbs from the thin fiber like material to Teflon in order to cure a leaks there.

I have to say, once again; I dislike Holley's a lot. I'm still fiddling with a choke problem on this set and we'll have to throw some more parts and money at it to get them right, but at least we stopped the leaks.

Stu Fox

[Robert D.]

Re: leaking 3x2 setup

Thanx guys ill start with the float levels i have good gaskets on the metering plates but if the float level doesnt help ill try the teflon gaskets.
Stu where did you get those gaskets from
thanx again
bob

[Stuart F.]

Re: leaking 3x2 setup

Bob;

Using the Teflon gaskets on the fuel inlet lock screws may have been a bit of overkill, but that was all I had from a small Teflon hardware kit that I had (contained various washers, screws, clips and brackets, etc.). I looked in my "Jeg's" catalog which has a lot of Holley parts, both original and aftermarket, but I didn't see anything specific other than what they have in mini kits and they did not specify what material they were made from.

Holley's are funny that way; if for some reason the floats are even just a bit on the high side and you get into a fuel percolation (heat soak) condition, they will find a way to leak externally from who knows where. This is unlike say a Carter AFB which will drip fuel internally, and at worst flood the engine and perhaps wash down the cylinder walls diluting the oil, but thats preferred over an external fire!

Stu Fox