AFB Carburetor Choke Housing Issue

[Dale M.]

I wanted to see what experience others have with my issues. I have a '64 300HP Vette. It has an AFB 3721SA carburetor. This has a choke with a tube from the exhaust manifold to bring heat into the choke. The choke housing has 3 post that hold the bakelite choke mechanism to the housing. These post are threaded for the 3 screws for the retainer for the bakelite. These are the screws used to richen or lean the choke. The inside of these post are very thin and mine have split and the screws are not holding. I recently purchase another housing and it has the same issues, but I am hopeful that are enough treads to still hold the retainer.

What experience do you have and it this repairable?

[Timothy B.]

Re: AFB Carburetor Choke Housing Issue

Dale,

My suggestion would be to drill and install a helicoil, I bet that will hold fine. Make sure to use a new gasket and tighten as there will be a vacuum leak if it's not tight.

[Donald H.]

Re: AFB Carburetor Choke Housing Issue

If your housing is similar to the one on my 1960 (picture attached), there may not be enough "meat" around the existing holes to drill, tap, and put in a helicoil. Looks like the way these are made is that to make room for the bakelite cover, the casting area on the inside of each post where the screws go is very thin.

If there isn't enough there to use a helicoil, I would suggest trying JB Weld. I have filled small tapped holes with JB Weld then put the the screw in place, then backed the screw out after the JB Weld sets up. You will need some sort of release agent to get the screw out. I can't remember what I used. I would also use a longer screw with a philips head to form the threads, instead of the short slot head screws in the housing.

Don

Choke housing.jpg

[Dale M.]

Re: AFB Carburetor Choke Housing Issue

Don, thank you. I was just getting ready to take a picture to show how there was not sufficient materials to drill and tap for a helicoil. I had considered using JB Weld, but was not sure how to use it for this situation. Mostly fill the holes with JB Weld then drill and tap, or use a screw as you suggested. Someone else suggested to back out the screw before its entirely dry. With my original choke housing, its always warped and not flat where the bakelite cover fits. Not sure if I could tap on this to get it flatten back out or it will break. My second one seems flat, so it just needs holes fixed and refinished. Thanks for you help and picture. Dale

[Joe L.]

Re: AFB Carburetor Choke Housing Issue

Don, thank you. I was just getting ready to take a picture to show how there was not sufficient materials to drill and tap for a helicoil. I had considered using JB Weld, but was not sure how to use it for this situation. Mostly fill the holes with JB Weld then drill and tap, or use a screw as you suggested. Someone else suggested to back out the screw before its entirely dry. With my original choke housing, its always warped and not flat where the bakelite cover fits. Not sure if I could tap on this to get it flatten back out or it will break. My second one seems flat, so it just needs holes fixed and refinished. Thanks for you help and picture. Dale

Dale------



JB Weld can be drilled and tapped. For a low strength, low torque application like this I think it would be perfect. Make sure you thoroughly clean and roughen the area where the JB Weld will be applied. After thorough curing, you should be able to carefully drill and tap it.

JB Weld is the "restorer's friend". It can solve many difficult-to-repair problems.