Type: single barrel downdraft
Material: air intake and fuel bowl are die-cast.
Throttle body is cast iron.
Styles: 28A: throttle shafts and choke shafts parallel
28B: throttle and choke shafts crossed
P: Packing or bushing in shaft holes
V: Vacuum operated power jet valve
X: Flange next size larger than standard
C: Automatic choke control
D: Equipped with degasser
R: Built in governor
| DESIGNATED SIZE | NOMICAL SIZE | THROTTLE BORE DIAMETER | S.A.E. STD. FLANGE SIZE |
|---|---|---|---|
| x9 | 1 1/8” | 1 5/16” | 1 1/4” |
| 10 | 1 1/4” | 1 7/16” | 1 1/4” |
| 11 | 1 3/8” | 1 9/16” | 1 1/4” |
| x11 | 1 3/8” | 1 9/16” | 1 1/2” |
| 12 | 1 1/2” | 1 11/16” | 1 1/2” |