Seeking Secondary Throttle Diaphragm Holly 4B

[swschulke]

Secondary Throttle Diaphragm Needed for a 4160 Holley.
all i can find is a housing at autozone.
the Secondary i have appers to drip gas... that cant be right...

[george worley]

I got mine in a carb rebilt kit from Holley.You could also get it from another old 4160 or 4150.They are usually ok just be carefull taken the diaphragm out. As to gas dripping where is it dripping from? Boosters or throtle valve or float bowel?

[DuckRyder]

Are we talking about the secondary actuator vaccume diaphram on a vaccume secondary carburator or something else?

[fitzwell]

if you can find anyone bright enough at oreally to read a holley catalog, the diaphragm should be listed in the back of the catalog, by list #. Where are you dripping gas from? The diaphragm should have nothing to do with that symptom. Have you been into the carb lately??

[DuckRyder]

Yep, I can't think of any way that a secondary actuator would leak gas (which is to say there isn't supposed to be any gas there, and I cannot think how it would get there.)

4160 should not have a secondary accelerator pump...

As far as the diaphragm, Holley lists quite a few on their website but you need to know the list number from the air horn to find the correct one. Once you find the number any of the "BOX" stores should be able to get it.

As to the fuel leak, need more information…

Vacuum Secondary Diaphragms and Service Parts

[swschulke]

Fountian of gas come from here... Perhaps this is why this leaks?

Well this is where it leaks, on the bottom I have not had a chance to look at it again as i am snowed in....


Again i am totaly oblivious to these types of repairs

[DuckRyder]

Ah, that is a bowl vent, I would say that you float(s) are very badly out of adjustment or perhaps a needle and seat or float has failed completely. The instructions which are available on Holley.com give good instructions for setting floats, if they won't set then you are probably going to have to go inside the carburetor with a renew or trick kit and a book.

I'd say that the secondary housing leaking is a symptom, not a cause but if enough fuel got in it could have damaged the diaphragm.

[My427stang]

Listen to the duck.

Under that vent tube that you showed in your picture is a device almost exactly like the float assembly in a toilet.

When the float bowl fills with gas, the float rises and shuts off fuel (just like water in the toilet), when the motor uses the fuel, it drops and lets more in

In your case, its not shutting off. Either the float doesnt float anymore (called "sunk") or the needle and seat is bad, or its misadjusted.

Replacing the parts needed to fix it is basically a carb rebuild.

I would recommend you find someone who has done it many times before to teach and show you, or go to a garage and bite the bullet and ask them to rebuild your carb because "the rear float bowl is overflowing"

[fitzwell]

Duck speakth the truth. Just for grins, try rapping the area around the back needle & seat assy with a 9/16 wrench. Possible a piece of trash has parked itself under the needle, causing the overflow. I'd get a book & study it before i took anything with a holley to a rapair shop. Not a lot of guys that really know hollys working in garages/service centers these days.

[swschulke]

After hours of fooling with it with no resulting change, it is now at a shop...