Carter AFB Carburetor

Carter AFB Carburetor


AFB Carburetor Identification

AFB Identification

Look for 4 numbers followed by a S. Example 3445S. You may find other numbers stamped on the carburetor, but they are usually the part numbers of the part they are stamped on. An example would be 0-1654S.

The AFB (Aluminum Four Barrel) carburetor was produced by Carter for original equipment cars from 1957-1971. The AFB was then available as a high performance 9000 series carburetor up until the late 1990’s. Weber is currently making the AFB now known as the Edelbrock.The accelerator pump controls response when pressing down on the gas pedal. Too little squirt will cause a flat spot or hesitation, too much squirt can cause black smoke and/or sluggish acceleration. You can change the action of the accelerator pump by repositioning the accelerator pump linkage.The metering rods are of a step design and are controlled by vacuum and metering rod spring action. At low speeds the metering rodis dropped down into the primary main jets, thus partially closing off the flow of fuel. At higher speeds and less vacuum the rods pull up from the main jets allowing more fuel to flow.AFBs use mechanical secondaries. Punch the gas pedal and the secondaries will open.The early AFBs were not rated with CFM statistics, but the later performance 9000’s were.Learn more about the metering rods, jets and metering springs. See all of our AFB parts
Carter AFB Jets, Metering Rods & SpringsAFB Jet & Metering Rod Sizes

Carter AFB Exploded Diagram


CFM Venturi Diameter Bore Diam
3721 575 1 1/4 1 9/16 1 9/16 1 11/16
4121 1 1/16 1 1/4 1 7/16 1 9/16
4122 1 1/16 1 1/4 1 7/16 1 9/16
4132 1 1/16 1 9/16 1 7/16 1 9/16
4133 1 1/16 1 9/16 1 7/16 1 9/16
4136 1 1/16 1 9/16 1 7/16 1 9/16
4137 1 1/16 1 9/16 1 7/16 1 9/16
4147 1 3/16 1 9/16 1 9/16 1 11/16
4148 1 3/16 1 9/16 1 9/16 1 11/16
4204 1 3/16 1 9/16 1 9/16 1 11/16
4205 1 3/16 1 9/16 1 9/16 1 11/16
9400 400 1 1/8 1 1/4 1 7/16 1 7/16
9500 500 1 3/16 1 1/4 1 7/16 1 11/16
9501 500 1 3/16 1 1/4 1 7/16 1 11/16
9510 500 1 3/16 1 1/4 1 7/16 1 11/16
9511 500 1 3/16 1 1/4 1 7/16 1 11/16
9625 625 1 3/16 1 9/16 1 7/16 1 11/16
9626 625 1 3/16 1 9/16 1 7/16 1 11/16
9627 625 1 3/16 1 9/16 1 7/16 1 11/16
9635 625 1 3/16 1 9/16 1 7/16 1 11/16
9636 625 1 3/16 1 9/16 1 7/16 1 11/16
9637 625 1 3/16 1 9/16 1 7/16 1 11/16
4758 500 1 3/16 1 1/4 1 7/16 1 11/16
4759 625 1 3/16 1 9/16 1 7/16 1 11/16
4760 750 1 7/16 1 9/16 1 11/16 1 11/16
4761 500 1 3/16 1 1/4 1 7/16 1 11/16
4762 750 1 7/16 1 9/16 1 11/16 1 11/16

Carter AFB Pump Link

Tip – The AFB pump link, links the pump lever to the accelerator pump. When you look at the link installed from the front of the carburetor, it should look like a ‘S’.

Free Carter AFB Manuals

Please do not distribute these manuals, but please feel free to give out the link to this page.

Carter AFB Carburetor Manual

Application Carburetor
V8 Fairlane, 500, Custom, 300, Police Interseptor 1957
2441s, 2441sa
V8 Montclair, Monterey, Station Wagon & Turnpike Crusier 312 1957
2441s, 2441sa
1966 Chrysler, Dart, Dodge, Plymouth 4121s, 4211s, 4132s, 4133s, 4136s, 4137s
1966 Lincoln 4147s, 4148s, 4204s, 4205s


AFB Accelerator Pump Problem & SolutionThis is a problem that one of our customers reported to us along with the email conversations.Sorry to bother you. I bought kit 4011 for my 1958 Cadillac Eldoradro, Carter 2862S AFB carb. Can’t get car to come off idle, wants to die. Warm, choke off. Idles O.K., 500-850RPM O.K. But when I push the accelerator to increase the RPM’s avove 850, it wants to die. If I coax it past this spot, at higher RPM’s it seems fine. A stream of fuel comes out the two accelerator pump jet nozzles when I depress the throttle, so I think the accelerator pump is O.K. I’ve adjusted the two mixture screws. There is a big air adjustment screw located between the two idle mixture screws, I tried to adjust that also. (But I don’t actually know the procedure for this air adjusment) Once it starts getting past the stumble, I notice drops of fuel coming out of the primary venturi’s, and dropping down onto the throttle buterflies. (I would think it would be atomized, not drops?) I’ve disassembled the carb a couple times, the float bowls are about 1/2 full. I’m stumped, I didn’t have this problem before I rebuilt the carb. I didn’t remove any shafts or butterflies. I would appreciate any ideas you have to offer. Second update: I should have checked this before I sent My first e-mail. My problem is a lean condition. If I pour a lttle gas down the carb while it is stumbling, itstops stumbling and smooths out. So the question is: What causes a just above idle lean condition? Third update: I fully closed the big air adjustment screw located between the two idle mixture screws, and this helped alot. I moved the accelerator pump rod down to the bottom hole, and this seemed to help some. I stll have an off-idle stumble, but it’s driveable, it doesn’t try to stall, just stumbles. The stumble is smooth slow acceleration, not punching it.
I took it apart again, and found a piece of debris partially plugging the small brass tube
feeding fuel to the primary venturi, (the small tube inside the bigger tube with holes in it)
The clue was, just above idle fuel would drip out of one venturi, (the bad side) No more hesitation, and I was able to open the air adjustment screw to set the idle speed.


Watch Our AFB Rebuild Videos

I recently purchased a leather accelerator pump for my Carter afb. I
soaked the leather in 3 in 1 oil overnight and installed the new pump
but am still a little unhappy with the pump shot. I have never been
able to get a very strong pump shot, even after adjusting the stoke
and installing the arm with the three holes since my carb did not have
the holes, only a single hole. Are there any tips or tricks to get a
stronger pump shot, there is currently a steady stream but it does not
seem to have any force behind it. I have two afbs and they both have a
very similar pump shot, somewhat weak. Is this just typical of afbs? I
noticed the Edlebrocks pump shot is substantially stronger and this is
basically the same carb, perhaps they upgraded it at some point. I am
still dealing with my off idle stumble and believe it may be a lean
condition due to weak stream from the squirters.

One odd thing I did notice. I swapped the two accelerator pumps from
my two afbs. While one pump inserted smoothly and tightly into the
well, the other pump would not, as if the well was a smaller diameter,
it seemed to bind up in the well. .The pump from the other still
worked well in the other afb. Confusing since both pumps appear to be
the 11/16 leather cup.

Any insight would be appreciated.

I have never compared an Edelbrock to and AFB squirt and that wouldn’t be a very good way to judge anyhow. If you are concerned about the main discharge not discharging enough, make sure the small passages are clear. Ethanol will leave residue in the carburetor passage ways. You will have to poke through the holes with wire. Test the pump before putting the top back on. Take a look at the Carter YF technical page. There is a video there on how to test the accelerator pump. Same idea for the AFB.

Soaking a leather pump in oil is not the best way to ready an accelerator pump and I’m not sure 3 in 1 oil is what should be used either. There are a lot of chemicals that do not play well with ethanol, so be careful. I keep all chemicals away from any carburetor. Only add 1 to 2 drops of regular oil before installing. Soaking in oil overnight probably has the leather swelled up past where it should be. I don’t know if the gas will eventually bring it back to a natural size or not.

Accelerator pumps do not necessarily fit tight in the pump well. Actually most don’t and shouldn’t, or the action will be too stiff.




114 thoughts on “Carter AFB Carburetor

  1. Hi Mike,

    I have 2 1995 7.4L Mercrusier inboards with a Carter AFB. They were both rebuilt a couple of years ago, and both have gone through accelerator pumps already. The symptoms always start with very hard cold starts, and what use to take 2-3 throttle pumps, now takes 15-20 to get enough fuel for start up. I use ethanol free fuel only. Any reason for this?

    • 2 things are making accelerator pumps fail.
      1. Chemical in the gas.
      2. Rough wall on the pump well. Gas has less lubricant these days. The pump wells should be polished with crocus cloth so the pumps glide easily.

  2. Mike I have a carter AFB 9000 it is a 9605 number the truck sat for a couple of years and had some bad gas that has made a problem for me. I have rebuilt it. I did change the metering rods back to the factory rods when I rebuilt it so I could start new with the adjustment. ( was living in Colorado when I first got thios and was able to adjust the metering rod to help it run.
    After rebuilding it I have had a real problem getting it to idle It will idle at 2000 rpm and die if it goes lower. it will not adjust. the truck at this point will not idle at all. I have worked and do not seem to have a vacuum leek I have replaced the baceplate gasket and pulled the PVC of the back and plugged the line. I have used carburetor cleaner and can not find anything that would cause this, with the exception of maybe some debris in the idle jets. I’m at a loss and do not want to put a new one on it.
    Thank you for your time

    • Hello,
      Check for vacuum leaks. Spray carb cleaner around the throttle shaft and base. A worn throttle shaft will cause a vacuum leaks. Also check the obvious places, intake gasket, etc.

      1st disconnect the throttle linkage to make sure it isn’t keeping the throttle open.
      Take the carburetor off and turn the idle screw out until it doesn’t hit the cam.
      Look at the throttle valves. They should be closed all the way. Very little light will shine through. If they have been put in the wrong way, then they may not be sealing.
      Make sure the fast idle screw is not touching the cam when the engine is warm and the choke valve is all the way open.
      Most likely something is holding the throttle valves open.

  3. Hi Mike,

    I bought a rebuild kit from you for my carter 9635sa. While I’m waiting for that to arrive, I just had a quick question.

    I have this carb on a 318 V8. Everything was fine until recently it decided it didn’t want to idle. If you let off the gas, it runs really rough briefly and then dies. Oddly, it doesn’t always do it. Sometimes it will idle just fine. When I give it gas it seems to have no issues, no stuttering or anything. Problems only at idle.

    I was just curious if you think there’s anything else I need to take a look at in addition to, or instead of, rebuilding the carb? Thanks!

  4. hi I have a carter with 9635sa stamped on the flange.[looks like 625 cfm according to your numbers] any idea what size main jets and rods would be in this carb?
    looking to put on a 79 302 and leaning it out a bit, thanks

  5. I have a Carter AFB Competition Series carburetor #9636SA (625cfm?). Will this work in a 1975 Chrysler New Yorker V8 with 440, 215hp? It has a competition cam and distributor. Thanks.


  7. I just rebuilt my carter 9637 when i smash the petal it hesitates for 3 to four seconds and then picks up speed whatvwoulf be my problem and do i cap the vent hole on the choke side thanks you

  8. I have a Carter AFB 4661s carb currently on an edelbrock C3B manifold on a .030 over 350 chev with an Elgin E923P cam, which the specs on the box say: Cam lift: .281 Intake & .296 Exh; Valve lift: Intake: .420 & Exh: .444; SAE duration: Intake: 270 & 280 Exh.; SAE timing: BTC: 27 ABC: 71; BBC: 76; ATC:32; Lobe Ctrs: Intake: 107; Exh: 117; .050 Duration: 204 Intake/ 214 Exhaust.; .050 timing: BTC: -5; ABC: 29; BBC: 44; ATC: -10.
    It is in a 2800 pound model A coupe hot rod using a turbo 400 trans (stock), and 9″ ford rear with 3.0 gears with 30″ tall rear tires. It was built as a road car. I have fuel pressure at 4.5 pounds. Fuel line is 5/16″ diameter throughout.

    My question is: given todays premium fuels (which is what I run in this car), and given these parameters, what would you recommend for jet sizes (main & secondary), metering rod sizes, and pick up spring selections (color, which indicates strength)for decent mileage and mid-range performance. Current set up is: Jets: Mains .095, Secondaries: .089….Metering rods: .073-.047…pink pickup springs. I am using manifold vacuum, as its non-EPA car in Oregon. Most driving is between 1800 and 3500 rpms. Thanks.

  9. Mike; I have a 3720s on my 64 Corvette, 327CI, 300HP, PG.I have been working for a month to get the choke to set when cold. I’ve followed several tips in the manual I have, without success. I have two different choke springs for it, one steel and one stainless. From my observation there seems to be a linkage part that is not set correctly? If you could suggest any manual or web-site that deals with chokes, it would be appreciated!

  10. Trying to get all the soup on a carter AFB #2814S Any information would be very helpful as the little metal tab is not on the carb. Thanks so much!

  11. I have a question for you regarding the Carter AFB. I’m building a traditional 60s custom and wondered what external visual changes have occurred with this carburetor over the years? What era does the current production of edelbrock carbs look like? Can you tell me in what years, did the carter afb undergo external visual changes? I need something era correct for a traditional 60s build I’m doing. Things don’t need to be right down to the proper numbers, but need to make sure what I have doesn’t look like an 80s AFB.

    I appreciate your time.

  12. Hi there. I have a Carter AFB Competition series #9504S and #1687 to the right of the #9504 stamping. I am not sure of the cfm of this carb. I know it is the competition series, but I might use it for a driver in a pick up.
    Engine is a 1979 Dodge 360. I had it bored .020, with stock dished pistons. Changed heads to older non rotator valves w/o little exhaust holes at bottom of ports. Cam is Mopar Performance only .268 intake and .272 exhaust and I offset initial cam timing -4 degrees for low end torque.
    I have an old Stealth intake for a carter carb and would like to use it because a Holley wont fit. Would this carb have adequate CFM for driving, towing and hauling in a 1979 Dodge 2wd D-150, auto trans?

    Other wise I have another Carter and no clue what it is.
    #4682S and this one has no air/fuel adjuster screws, just caps.

    Any advice would be helpfull as well as rebuild kit/s like I see have been posted.

    • It’s probably a 500 CFM. It should do OK on the 79, but a 600, or 650 would even be better if you run across one. The older AFB 4682 is for a Plymouth 1970-71 and is an AVS. Don’t know the CFM.

  13. Are the 9636S and the 9637S carbs basically the same except for the added Ford linkage assembly? Found a 9637S in a box of parts that came with a 65′ Barracuda I recently purchased. 35 years ago the original owner pulled the the 273 and dropped in a 73′ 318 and never completed it. Trying to figure out which carb to run on this 318. Thanks for any info you may have on this.

  14. Trying to ID my Carter AFB 1D79002 and do you have kits and spec book. It is on a 1978 v6 Buick built by Kenney Bell and runs out of poop at hi revs.
    Thanks ART

  15. hi i have a carb with carter AFB competition series on the front webber on the side
    number 9605 3507 can anyone tell me what it is off and what engine its good for put it on my 75 corvette no good many thanks if you can help paul

  16. That is correct then send me any damage to the carburetor just to the base of it , some melting. I am trying to touch a photo but cannot.

  17. I am resurrecting my grandpas 65 riviera , I took off the carb to change the gasket there appears to be no heat plat and damage to the aluminum, is it toast or can I get it rebuilt .
    Many thanks

  18. I recently overhauled both 9000 series carbs with your kits on my twin 454 Mercruiser inboards on my boat. Carbs are 9772S. One engine runs good but the other has a bad bog as primaries open after accel. pump shot. It will not transfer to secondaries without stalling. I noticed almost no fuel coming from the right side primary nozzle while this is happening while the other engine has visible fuel flowing from both primaries at the same throttle position. I removed and disassembled the problem carb and found no blockages at all. I am unsure about these staggered jet sizes, the problem primary has a noticeably smaller jet than the rest of the jets. I believe these have never been disassembled prior to this. Choke and accel. pumps are working great. Any input would be greatly appreciated! Thank You very, very, much!

  19. Hi Mike! So glad to find your site. Do you know what AFB this is and the rebuild kit for it? The number on the base is 3E4 9637S. It has an electric choke and Ford kick-down. Sure hope you have a kit for it that’s compatible with today’s fuels.
    Thank you very much!

  20. Hello,
    I recently purchased a 1967 Plymouth Barracuda Formula S convertable with a 273 ci. with automatic trnsmission.
    The 273 has an AFB no. A7 4295S, which is stamped on the right side front flange and the aluminum tag on the upper deck. I can find no reference to the no. 4295. Can you help me here with any information about this carb.
    The engine seems to run OK but I intend to service the carb, clean it up and would like to put a rebuild kit in it but I don’t know which kit to purchase.

    Thank for any help….Robert

  21. Hallo,
    I have a carter afb 2794s canadian police spec (desoto, 383 chrysler engine from 1960) and i need to know what the CFM is of the carb.
    And if i buy a new edelbrock carb what would i need for the 383 chrysler and performs like the old carter 2794s carb?
    Can you help me with it?
    Kind regards
    The Netherlands

  22. I have a ’69 Dodge Charger with Carter AFB. Need help in getting the choke set properly. Spring is set down in the intake manifold. I have taken the spring and put it in the freezer and it appears to me that it does the opposite of what it should do.
    This choke adjustment seems rather hokey!! Thaniks for any help.

    • I don’t remember the AFB divorced choke specifically, but some will have an adjustment on the coil itself, others are adjusted by bending the rod that goes from the coil up to the choke lever.

      You will 1st have to determine which way the coil works. Then with the engine cold bend the rod so that the choke lever is closed. Be sure nothing is holding the choke open or closed besides the thermostat. Once you get it closed when cold, warm the engine to operating temperature. The choke should now be all the way open. If not, then the thermostat may be bad.

  23. I just bought a Carter AFB Competition Series carb. # 9605s 2774
    Can you tell me the CFM & will it work on a chevy 350 with 9.8 compression. Edelbrock Stage 2 cam?

  24. I am trying to find an accelerator pump for a Carter AFB 4758S. I think i prefer the rubber over the leather. But i’ll take what i can get at this point. Do you know where I can find one? I dont know the diameter either since the leather on my current on is completely gone. Do i measure the diameter of the metal plunger without the leather? Or the diameter of the shaft it sits in? Thank you for your reply.

  25. i recently acquired a carter 9410 carb – i was told it was new old stock
    i can read the jets @ 392 & 371, but i cannot read the rods at all I think I make out 16-421? but this does not make sense from what ive found.

    Can anyone tell me what the original rods should be?


  26. my Brother passed away and we found a Carter AFB Competition Series
    carb #9605s 0343
    Itrying to find information on this. I would like to sell it

  27. I was rebuilding my 9400s and founf the choke housing piston is very stuck and wont move – it wants to tear the arm/connecting rod off the piston down in the hole?
    Do you have any suggestions – i wanted to make this manual choke anyway and the coil and that plate aren’t there?
    I thought about running an arm off the side of the carb that would clamp the outside of the choke cable and just connecting it to the choke tab where the linkage would go – if my choke housing worked?
    Considering i want it to be manual choke – do i need to fix the piston and how could i best accomplish this? I did see one carb that had an arm off the top ( behind airhorn) that was holding the choke cable jacket and was attached to the top tab?

    didnt know how many choke parts you have?



  28. hi mike it’s ray are the carb’ I have ok for a 671 blower or do I need 9000’s and do you have 2 good 9000’s for sale and how much would they cost

  29. Hi mike nice vidios but I have 3 AFBs #s 3860sa also 3644 I want to rebiuld these and put them on a 6-71 blower 413 engine I need good kits can you tell me what CFMs are they are how much are the kits are will they run good on the blower do you have a phone # to call to talk

  30. Mike, I rebuilt my Cater AFB 9000 Series with your kit and videos. Worked out good. Old 1986 F350 runs good, but now that cold weather is here, it is not working correctly. During the summer I could start it up and the choke would be one but a quick pat of the gas and it would go off. Now it want go off at all. After starting. It will go up to 1500 RPS. a quick pat of the gas will bring it to 1,000, but as I am driving it, it will increase again. I can drive for miles, 20 to 30 miles and no matter what I do it will not ideal down. It stays at 1500 RPS. If I stop after it is warm and restart, it will ideal down to 700 to 800 RPMs. I tried turning the choke to decress by two marks from the normal and it did not do anything. I don’t know what I can do from here?

    • I can only make a guess because it could be a lot of things, but did you take the throttle valves apart? If you did make sure they haven’t come loose. They could be moving around and don’t wait too long because if the screws are coming loose they could fall into the engine. Aside from that it could be a bad thermostat, or some part of the choke linkage (or lever) is sticking. Check all of the screws that hold the linkage together. I don’t have a 9000 around right now to look at, so I can’t point out anything specific.

      Hope this helps.

    • And the carb is either a AFB or a AVS carburetor.
      The AVS has a spring loaded secondary valve. the AFB is inside the secondaries down under the venturi’s and is weight controlled.

  31. I believe they were 575cfm’s,
    What size is the air horn opening?
    there were 2 a 4-1/2″ and a 5-1/4″ does it look like the older ones with a round opening or like an edelbrock?

  32. I have a Carter ABS from a 1969 AMX. I did not see the part number for my carb in your tech information. Number is 4662S. Any idea of CFM on this carb?

  33. I just rebuilt my Carter AFB. It had a real dead spot before. It idled perfect. Now, there is no Idle and it pops and misses. As soon as the choke lets up it dies. Can you offer a suggestion?

    • The 1st thing I would look for is vacuum leaks. Check the flange gasket for fit. Other than that, you will need to carefully check the assembly process to see what went wrong. It might just not be getting enough fuel. Check all of the passage ways to make sure they are not plugged.

  34. I am trying to figure out what kit i need to order for my 9100s – do you know if it is 450 or 500 CFM carb or maybe 400?

    My dad died 9 years ago and the nice buick 231 rebuilt by a race shop isnt running worth a crap? I figure i will put it in cleaner for a day or two – then replace the parts since it worked before he died.

    Also it will be 4 wheeling and i thought they sold different springs or some kit for off road?

    The intake is a edelbrock performer with performer cam but it has allot of power, or did?

    Thanks for any help,


    • If 9100s is really the carburetor number, then you have a Carter TQ, or Thermoquad carburetor not an AFB. The kit for that carburetor number can be found here:

      Off hand I don’t know the CFM. I will try to find out and post it on the TQ technical page.

      As far as 4 wheeling, I wouldn’t do anything to the carburetor until after you rebuild it and test it out. Only then should you consider tinkering with it, because that is where your troubles could begin. 🙂

      Enter your carburetor number in our search box and the correct kit will be displayed.

  35. Mike, have a 9625 I’m rebuilding, when I pulled the Accell Pump Nozzle there wasn’t a ball or counter weight as shown on your video. What I extracted is a small needle valve. Kit has the needle valve and a ball, but will not allow nozzle to seat properly if both used, due to length. Due some 9625’s use set only?

  36. I’m runing dual quads on a 5.7 boat 202 aluminum heads 64 cc chambers straight plugs.jegs 350 260 hp goodwrench to start with stock cam 1.6 rockers
    jets running are 86 pri 71 mains 6252 rods 1 and a half turns on the avs
    34 degrees full adv after 3000 mallory marine dist no vaccum mallory coil
    500 cfm avs carbs and have probably possibly tried every combination possible
    jets pri+main rods etc. last try to really split hairs is to try a 71/74 main combination with a 62/52 and a 65/52 rod split up rich rod in the lean main side.etc. vsa versa front carb
    running 1/2 turn on the avs function to start motor is providing great top end and a lot of mid range torque! good combination a lot of time spent to get right .
    also had to go to mikes carter afb for /to get the smaller jets in the mains 71/71/70s he had them in stock hope this helps out some one.!!!!!!!!! rollie t.

  37. I have a Carter AFB 4bbl Carb. with the numbers of 4B4 9637S stamped on the right front flange.. I am looking for a complete rebuild kit for this carb..Can you help me with this …. Thank You Stanley Lee

  38. I have two carter carburetors with a tag# 3681s. By the chrysler part and casting numbers book these fit 1964 hemi. I would like to see a photo of a 3681s carburetor to compare to what I have, to make sure this is right.

  39. I have rebuilt a Carter AFB 9635SA 2 times, and it won’t idle smoothly at all, it misses and pops, I had another one on there and it ran fine, but I sold it because I have too many carb’s, I found the primary jets are counter sunk in there holes 1/16 to 1/8″ down, I had stock 70×47 metering rods and it ran awlful, changed to 75×47 rods and it improved but still rough, changed rods to a Plymouth 318 2991S rods 16-120 and it ran much better but still rich, can smell it. Jets are pri. .100 and sec. .095, mixture screws are new but backed out 4 turns. what’s with this Carb, is it trash, I’ve soaked it in chem dry and pure acetone also and it’s clean.

    • Hard to say here, but I doubt your problem is with the jets or metering rods. Something is installed incorrectly, floats too high. Simply too much fuel getting in. Test your floats and make sure they don’t leak.

      • I will check my floats, it seems to have the idle mixtures screws out 3 turns to idle, and it idles with popping out the exhaust and it’s rough.
        No fuel is leaking out the shafts or down the bores

  40. Hello Mike

    Trying to find what kind of carb i have.
    Carter AFB, E1 9500SA,

    Can you help me ?

    Greeting from Sweden
    Love the Videos 🙂

  41. 1967 GTX, 4127s have been into this card 50 times. Can not get why the accel’ pump won’t work until half throttle. It seems it’s in the body. I have three 4127s, the other two work. All adjustments are spot on, bench test seems good, put on car, no dice. Traded inlet check, plunger, top, needle, squirt-er, cleaned bore, blows clear, take out squirt-er, hold finger on hole, no leak back to bowl………….I have only one hair left to pull, HELP

    • The 1st thing that comes to mind is the distributor advance. A distributor not advancing correctly will act just like a bad accelerator pump.

      Assuming the distributor is OK, turn your attention to the accelerator pump circuit. You 1st want to be sure the adjustment to the pump arm is such that when you press on the throttle, the pump starts to move right away. Any slack will cause it to hesitate.
      The next thing is to see if any fluid is escaping when the pump is depressed. You will need to remove the top of the carburetor (should be off the car), and remove the pump jet housing (I would call this the pump discharge). Fill the pump housing with fluid. Plug the discharge with your finger and press down on the accelerator pump. You should get some pressure. If not, then the fluid is leaking back through the check ball into the float bowl.

      Assuming there is nothing leaking back, fill the pump housing with fluid, and press down on the pump. Fluid should shoot up through the discharge hole right away. If not, then there is a blockage somewhere.
      By the way, be sure the check weight is in the discharge hole.

      We use mineral spirits for this type of testing.

      Make sure your secondary air valves are working. When the secondary plates are opened, the air valves will not allow air through the plates until the engine can burn the extra air and fuel mixture. This prevent hesitation during acceleration.

      Another possibility is the metering rod springs. These springs move the metering rods depending on the engine vacuum and bad or incorrect springs could also cause hesitation. This is especially true when running any kind of performance cam resulting in lower vacuum. Eperiment with different springs to see if the hesitation is removed.

    • Is an R-2 supercharged? If so, those carbs must be assembled a bit differently, with lots of attention paid to sealing in critical areas.

      Otherwise, I would guess that the carb keeps getting “rebuilt” with needles & seats which leak such as Pacer part # 25-278A. There is no reason for a raw gasoline drip into either venturi unless the bowl is overfilled. Of course, he could also have a hot-soak condition (gasoline percolation from heat).

  42. I have a Carter AFB 3507S in my 1963 Studebaker Avanti R-2. I have had rebuilt several times.but I always end up with the same problem. It will not hold an idle and a small amount of gas drips into the right primary venturi at idle. What is up with that?

  43. I need to get a rebuild kit for a Carter AFB carburetor that is currently on a 327 chevy engine from 1963…not sure of the year of the carb, but do not find numbers on the carburetor where your diagram indicates….it’s stamped on the opposite side front (if in the driver’s seat, would be right front corner; there is not metal tag). Number stamped there is DI 9625 SA . Also, on the right side of the carb housing is either a C- or O-1862. I now see from the discussion above that 9625 is one listed and the housing number is a parts number. However, the numbers used to indicate compatibility on the ordering page do not coincide with these numbers. Can you advise as to what kit might work for a re build?…will 4011 work?


  44. I have a 66 Barracuda with a 318 (purple cam) and 3108S carb. I went to adjust the air/fuel mixture screws and turns them all the way in and it continued to run. I figure this is why it is running rich as well as small hesitations at lower speeds. The car doesn’t hesitate when I step on it, but I think it could run better. Any suggestions?

  45. I rebuilt the 3720s afb now it will not idle. It must have a vacum leak as I can get it to idle by partially covering the primary opening with my hand. I have removed and plugged all hoses and ports on the carb. Also have sprayed WD-40 at the base and throttle shafts for vacum leaks. I believe it to be an internal problem in the carb. Help! Please.

    • The 1st thing you will need to do is rebuild the carburetor again. Spraying WD-40 around a carburetor is a sure way of ruining your gaskets. Ethanol + WD40 = acid.

      The other side of a vacuum leak is not having enough fuel in the carburetor. Recheck your float level and make sure the needle and seat are working properly. Did you put the clip on the float and the needle? This helps lift the float when more fuel is needed. Also did you use a quality US made kit like we sell? We won’t use any imports because the needle & seats are trouble.

  46. I recently rebuilt my Carter AFB 4119s carb for a 1966 Plymouth Barracuda with a 273 using a carb kit from your website. Unfortunately, I broke both of the idle mixture screws in the process. I have been trying to find replacements, but they are all too small in diameter. Do you know how I can locate the larger diameter screws, other than buying another AFB core of the same vintage at a swap meet?

  47. HELP ! I have just recently rebuilt my AFB #3461 for my 327 vette . The engine starts up and idles OK. However under acceleration whem my seconderies are beginning to open the engine abruptly shuts down (as if its run out of fuel) It will continue to idle though. I have checked my float level and float drop. they seem ok. What have I done wrong? Thanks for your help. Joe

      • Blow air thru the secondary venturis,it should draw fuel thru the passages.Make sure the secondary throttle and choke plates are wide open.If you have the spring loaded choke plate it might be opening to quickly reducing vacuum across venturies. good luck

  48. Mike,
    I am in need of the base assemble for a Carter 9627 carb because one of the mounting ears on my AFB carb has cracked off. Is that any possibility of buying a used base for my carb from you? If not do you have any suggestions as to where I could purchase a used base.

Leave a Reply

Your email address will not be published. Required fields are marked *