Here is where we try to identify the screw sizes of the Carter YFA carburetor. We list our part number so you can click on the link and you will be taken to the product. Your carburetor must look exactly like the below pictures, or the screws may be different.
A 8-32 x 1 80-87
B Spring 66-51
C 10-28 x 3/4 80-86 which is actually 7/8 but will work.
D 10-32 x 1/4 or 3/8