Carburetor Trouble

[Guest Lloyd 1955]

Just installed re-built carb from Kantor. Rochestor 2 barrel on 55 Pontiac. starts but barley runs. It is leaking gas badly so I stut it off. Any ideas?:confused:

[hwellens]

I assume the fuel lines are not leaking and the fuel is leaking out the top. If so, a couple causes could be the float is set too high or the needle valve is not seating. If leaking elsewhere, the body bolts were probably not tightened enough. I would call Kantor. They may just send a replacement.

[NTX5467]

I concur, let THEM do the work to figure out what's not right.

NTX5467

[Guest]

Sounds to me like float /needle/seat trouble. In shipment the needle could have wedged itself in the seat chamber-it even could have become unhooked. You could try a little tapping at or near where the fuel line screws onto the air horn. Just lightly tap the air horn in that spot. My friends Buick sometimes does this and on a AACA tour last year the needle wouldn't seat and it flooded-I just tapped the area above it and it's been running good ever since. If you don't want to open it up , sending it back is your only recourse.

D.

[c49er]

Maybe your tank has sediment in it and it was flushed into the needle and seat of the kanter rebuilt carb. Now it is flooding out.

Most carb rebuilders do state to use a new fuel filter before installing and running new carb.

As stated above sometimes lightly tapping on the carb top with a wooden handle can help the needle and seat close up to a working condition if the needle was stuck open.

[carbking]

The first question is are you using the original fuel pump or an electric replacement. If electric replacement, a regulator may be necessary.

Assuming that you are using the original fuel pump, then the previous comments about tapping the area of the fuel inlet with a wooden on plastic item may solve the issue. If it does not, I would suggest calling Kantors.

We suggest whenever installing a carburetor to fill the carburetor through the bowl vent to minimize issues such as the sticking needle.

Jon.

[Guest Lloyd 1955]

Thanks I will tap the carb. If it doesn't work back to Kantors.

[D Yaros]

We suggest whenever installing a carburetor to fill the carburetor through the bowl vent to minimize issues such as the sticking needle.

Jon.

Where is, how does one find the bowl vent on a Rochester carb. Aybody have a pic? How does one fill the float bowl this way?

[Guest]

The vent is a tube going from the air horn to the float chamber. This is a picture of the air horn and in the casting at a angle to the float chamber is the vent;

http://www.hotrodcarbs.com/images/largeparts/IMG_0656.jpg

This is a picture of a four barrel for a 56 Pontiac..notice the vent tubes (2) cut at a angle going to the two separate float chambers;

http://www.pontiacsafari.com/L1EarlyV8Pontiacs/56DualQuad/RickGonserArticle/image007.jpg

here is a later 4gc with four vent tubes... cut at a angle;

http://www.pontiacsafari.com/L1EarlyV8Pontiacs/56DualQuad/RickGonserArticle/image008.jpg

Here is another picture of the first 4bbl, the tube can clearly be seen sticking into the air horn.. This is a 56 Pontiac factory 2-4bbl set up;

http://www.pontiacsafari.com/L1EarlyV8Pontiacs/56DualQuad/RickGonserArticle/image009.jpg

D.

Edited January 29, 2012 by helfen (see edit history)

[D Yaros]

Got it now. Know exactly what you are talking about. Thanks! I appreciate it. Helps me alot.