The Zenith Carburetor is a two-stage carburetor with throttle valve diameters of 35 mm. for stage I and 40 mm. for stage II.
It consists of four main parts which are bolted together:
1. Carburetor Cover (choke plate, idling speed air hole and transition air hole);
2. Plate block (with all jets, accelerating pump, float and float chamber venting valve);
3. Float Housing (with mixing chamber and venturi for stage I and stage II );
4. Throttle Valve Section (with throttle valves, idling speed mixture regulating screw and bypass bores).
The Zenith was used by Mercedes in type 220Sb from 1964 and up until 1972 in the 250/8.