I have a small collection of Carter afb 625cfm “compe***ion series” carburetors. I thought they were all exactly the same but they are not. So far I have identified two types of secondary boosters. One has larger air bleeds with tapered bottom feed tubes. The other with smaller size bleeds and straight tubes. What’s going on here? Also, some of the secondary air valve counter weights seem different and have different numbers stamped on them. Do those numbers actually mean anything? Will try to post some pictures tomorrow.
The original Carter Compe***ion Series carbs came out in 1969. Part number stamped on the edge of the mounting flange is 4759s. There was only one 625 CFM (manual choke); unlike the 500's and 750's that came both as manual choke and chokeless. The tiny stamped numbers on the secondary clusters should be 1099 and 1100. The secondary airvalves are one of the little known methods of tuning on the AFB. Carter issued dozens of different ones. These have 3 variables: (A) shaft length (longer, and shorter), (B) the m*** of the weights, and (C) the attack angle of the blades. The numbers on the weights are the number for an individual weight only. The same weights might be used on a different length shaft, or one with different angled plates to form a different airvalve. The different airvalves are using in tuning the timing of the opening of the secondary. Without going to the microfilm, I cannot tell you what numbers should be on the weights. After Federal Mogul bought Carter and redesigned the AFB in the mid-1980's, additional carburetor numbers may have been issued. Don't know. If issued, they would have been in the 9000 series. I do nothing with these carbs, so don't have the information. Jon
I guess all the secondary flapper valves I have are the same. They are all the same shape and dimensions and start with a 221 number.
The AFB that had the different type secondary boosters is a 9000 series but has “Carter AFB” cast into the main body. I’m gonna ***ume it’s a FM. It also has an accelerator pump lever with 4 holes instead of the usual 3. My other AFBs have the Weber logo cast into them. The attached pictures are the secondary boosters side by side with the FM on the left and Weber on the right. You can see the differences in the feed tubes and air bleeds.
None of these are genuine Carter. As previously stated, the only genuine Carter Compe***ion Series 625 was 4759s. Weber/USA was one of the companies that produced the clones for FM. The genuine Carter Compe***ion Series carbs: 4758s - AFB 500 CFM manual choke 4759s - AFB 625 CFM manual choke 4760s - AFB 750 CFM manual choke 4761s - AFB 500 CFM chokeless 4762s - AFB 750 CFM chokeless 4846s - TQ 850 CFM manual choke, press-in jets 4846sa - TQ 850 CFM manual choke, screw-in jets 4847s - TQ 1000 CFM manual choke, press-in jets 4847sa - TQ 1000 CFM manual choke, screw-in jets Jon.
“None of these are genuine Carter” Thanks So what do you make of the two different secondary boosters? Is one better than the other? Does it matter? I guess I should stop calling these “Carter AFB” and just call them Edelbrock carbs. They seem to have more in common with the Edelbrock.
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