1963 AFB Idle Needle Valve Ports

[Joseph S.]

After freeing a frozen idle adjustment needle valve on an original AFB from my 300HP '63 coupe, upon inspecting the throttle bores it seems both idle adjustment screws (I could have done this) were overtightened and damaged the seats and the ports. Does anyone have any experience how ( or who) to repair these ports or if they need to be repaired at all. Have not run the car since I discovered it. Thanks Joe

[Edward J.]

Re: 1963 AFB Idle Needle Valve Ports

Joe, I think you may have a problem,since the throttle body is part of the float bowl. to repair anything like that maybe a issue as no room to rework, there are a few guys on driveline that rebuild carburetors maybe you can call one of them and ask,If not I would start looking for a junk carb for spare parts, sometimes E/bay has them.

[Timothy B.]

Re: 1963 AFB Idle Needle Valve Ports

Joseph,

You may get a different opinions here but if that were mine I would put it back on and try it, the damage does not look unsafe to me. That being said don't tighten the screws to the seats any more, go easy and see if the idle will adjust smooth. The correct adjustment screws should taper to a point and not be rounded blunt so make sure someone has not changed them. If that's a 3461 I would call some of the well known carburetor rebuilders and inquire if there is any way to repair.

What you see is a common problem, I think in the future you should look for a nice used 3461 without damage to install. To be honest, either excessive heat damage from the hot slot or damage like you show are probably the two biggest things that destroy the AFB castings.

You now know what to look for when shopping, if you find a nice 3721 it's the same carburetor (maybe better) with some tuning revisions and it will work exactly like the original. Don't give the original up, keep it with the car if you swap.

[Joseph S.]

Re: 1963 AFB Idle Needle Valve Ports

Joe, I think you may have a problem,since the throttle body is part of the float bowl. to repair anything like that maybe a issue as no room to rework, there are a few guys on driveline that rebuild carburetors maybe you can call one of them and ask,If not I would start looking for a junk carb for spare parts, sometimes E/bay has them.

Ed
I was sort of afraid of that - I think I'll give it a try on the car, and check out what carb rebuilders can do . Ultimately I'll probably be looking for another. Thanks Joe

[Joseph S.]

Re: 1963 AFB Idle Needle Valve Ports

Joseph,

You may get a different opinions here but if that were mine I would put it back on and try it, the damage does not look unsafe to me. That being said don't tighten the screws to the seats any more, go easy and see if the idle will adjust smooth. The correct adjustment screws should taper to a point and not be rounded blunt so make sure someone has not changed them. If that's a 3461 I would call some of the well known carburetor rebuilders and inquire if there is any way to repair.

What you see is a common problem, I think in the future you should look for a nice used 3461 without damage to install. To be honest, either excessive heat damage from the hot slot or damage like you show are probably the two biggest things that destroy the AFB castings.

You now know what to look for when shopping, if you find a nice 3721 it's the same carburetor (maybe better) with some tuning revisions and it will work exactly like the original. Don't give the original up, keep it with the car if you swap.

Tim
Thanks for the input- hopefully the carb will still work, or a rebuilder can do something with it. However I probably will be looking for a new core
thanks Joe

[John D.]

Re: 1963 AFB Idle Needle Valve Ports

Joe, If necessary a good machinist may be able to make an insert to repair your casting. Now if this were a '57 to '65 fuel injection part I have a friend who could do such an operation for the idle fuel screw.
The repair if possible would be costly. In your case AFB parts/carbs are all over the fleas and on Ebay.

One other thing here is to quickly discuss the idle fuel screw needles. There is a lot of variations in those needles. Not interchangeable like we think they are.
Joe you might want to contact our NCRS carb guy which is Gary Hodges from Salem, OR. His address, etc is in the Restorer. John

[Joseph S.]

Re: 1963 AFB Idle Needle Valve Ports

Joe, If necessary a good machinist may be able to make an insert to repair your casting. Now if this were a '57 to '65 fuel injection part I have a friend who could do such an operation for the idle fuel screw.
The repair if possible would be costly. In your case AFB parts/carbs are all over the fleas and on Ebay.

One other thing here is to quickly discuss the idle fuel screw needles. There is a lot of variations in those needles. Not interchangeable like we think they are.
Joe you might want to contact our NCRS carb guy which is Gary Hodges from Salem, OR. His address, etc is in the Restorer. John

John
Thanks for the input, I've actually talked to a carb restorer who wants to weld up the ports and redrill. Not sure I'm ready for that.
I'll talk to Gary - thanks Joe