Identifying Carter AFB Carburetor Bolt Patterns 

The Carter AFB carburetor was used on many marine installations over the years. The bolt pattern of the "early" AFBs differ from the later models. When replacing an AFB carburetor with a new Holley marine replacement carburetor it's important to know what you've got. The illustrations, at left, will clarify the two different bolt patterns used on the Carter AFB carburetor. 

Early Carter AFB Bolt Pattern 
When replacing with a Holley model 4010 carburetor the following is required: 
...... P/N 17-7 adapter ...... P/N 717-5 throttle cable bracket (or P/N 17-23
spacer) ............placed between the carburetor and adapter to ............prevent vacuum leaks. 

Late AFB Bolt Pattern 
This pattern is exactly the same as the Holley model 4010, square bore carburetor. No special adapter is required for this installation.