What I found inside my 4139 4140 AFB’s

[dan juhasz]

I bought a couple of rebuild kits and four floats with the intention of performing a thorough cleaning and basic rebuild.
Had an unusual hard time just to remove the air horn. Seemed like it was hanging on the brass air bleeds that poke through the air horn. Seems the choke shaft actually wore a significant divot in both tubes. The choke shaft is loose sloppy in the air horn. Has anyone ever experienced this. It would need to be rebushed to avoid damaging the bleed tubes. How do I fix the air bleeds?
Then there was some day 2 butchery, apparently someone took a file to the metering rods ruining them. I’ve looked at all the old strip kits and those rods are special to the hemi calibration. How can I resolve that problem?
Appreciate any suggestions
Dan

 

[HALIFAXHOPS]

@Dragon Slayer might know

 

[Geoff 2]

Anybody's guess as to idle tubes. Looks like they have been squeezed with pliers or vise. The orifice will likely be in the 0.028 -0.036" range & they look ok. Try some numbered drills or wire until you get the right size & see if it will pass by the squeezed section. If it does, no harm done. If you cannot get it passed the squeezed section, there could still be enough room for fuel to pass because the squeezed section will not be a round hole, it will be an oblong shape. Have to try it & see....
Very rough job on the met rods. I have filed met rods to increase fuel flow. But it looks like the main section of the rod near the # has been filed & that section of the rod is not part of the fuel metering. ??

 

[Dragon Slayer]

Those venturi are shot because they wore through tube. Your High speed air bleed is now much larger then the calibrated value. The Choke shaft has slots that clear those tubes. Some one did not know you can not remove the choke shaft without removing top. Or they used an in correct choke shaft. Yes I have seen this before. Along with wood screws used to plug holes. Real morons. Yes I know it is their carb so they can do what they want. But jeez. What does your choke shaft look like. The picture shows the choke shaft with slots in upper right. It is a 70 carb, but all the hemi carbs have those slots. Other shafts for certain makes don't. They are solid.

 

[Dragon Slayer]

The 16-440 rods are unique to 66-67 rear hemi carbs. They are .0665" x .058" calibration. Your going to have to find something close, originals hard to come by.

You can try to solder/braze that tube closed. make sure you have a .031" bleed hole through. Than modify your choke shaft or get a correct one with the slots. Looking at your picture it looks like a solid shaft through the hole in top that the high speed venturi tube comes out of.

 

[dan juhasz]

The 16-440 rods are unique to 66-67 rear hemi carbs. They are .0665" x .058" calibration. Your going to have to find something close, originals hard to come by.

You can try to solder/braze that tube closed. make sure you have a .031" bleed hole through. Than modify your choke shaft or get a correct one with the slots. Looking at your picture it looks like a solid shaft through the hole in top that the high speed venturi tube comes out of.

It was my guess that the choke shaft had to be incorrect. I figured it needed to be chamfered to clear the bleeds. Thanks for your input and at least I know the drill size if I can indeed repair the bleeds.

 

[RJRENTON]

It was my guess that the choke shaft had to be incorrect. I figured it needed to be chamfered to clear the bleeds. Thanks for your input and at least I know the drill size if I can indeed repair the bleeds.

I feel for your predicament......its totally just how many self proclaimed carb experts thst exist that have no clue how things are designed and why. The subtlety of having relief notches in the choke shaft to clear the primary booster air bleeds, while unusual, would likely escape the typical carb hack and use the Army method to resolve.....Army Method = Brute Force and Blind Ignorance......
Hopefully, possibly thru the use of a sacrificial AFB, you can recover you can recover the damaged parts and put your carbs back to correct operation. Please let us know how you make out.....regards....
BOB RENTON

 

[dan juhasz]

Anyone reading this thread if you have any parts that could help let me know. Used booster Venturi’s, metering rods close to my needs etc

 

[Cranky]

Anyone reading this thread if you have any parts that could help let me know. Used booster Venturi’s, metering rods close to my needs etc

It most likely would be good to start a wanted ad looking for the parts you need as it would probably get more attention.

 

[AR67GTX]

I went through my 4139, 4140 carbs last year with Dragon Slayers help. Most of what you probably need can be found at Mikes Carburetor Parts. I cant remember without checking note but I think it was the 16-440 rods. I went through their list of reproduction rods and found the ones closest to the originals, just slightly richer. He should have any jets you need. You might check on eBay for a set of 16-440 rods as the stuff pops up now and then. Not sure what you will have to do with those air bleeds though - Bubba sucks.

 

[AR67GTX]

I looked back and I had the 440 rods but the front carb rods were wrong (should be 16-136). Those are what I had to match up to the closest rod from Mikes Carbs.

 

[dan juhasz]

I looked back and I had the 440 rods but the front carb rods were wrong (should be 16-136). Those are what I had to match up to the closest rod from Mikes Carbs.

Where is mikes carbs so I can google and get some contact info

 

[AR67GTX]

Here’s his site. He has lots of info and videos on the site but it takes some digging to find some of them.

Mike's Carburetor Parts
This one digs down into afb specific parts
Carter AFB Carburetor Parts