If anyone is thinking of converting to a Zenith Carburetter, a new one is difficult to set up with older Reliant engines. Paul Haley, Northern Area Rep, has suggested the following settings. for example, the original main jet was about 103, and was reduced to 93 to meet emission regulations. Unfortunately this reduces the performance of the older engines quite considerably. Providing your engine is exempt from emission testing, Paul recommends you check yours is about 103.
Venturi 20mm
Main Jet 92.5 t 95 (100 – 105 works better with older engines)
Correction Jet 160 – 175
Auxilary Jet 60
Economy Jet 60
Auxilary air bleed jet 1.20
Needle Valve 1.3 – 1.5
Needle Valve Washer 2.0mm
Float 11
Idle Tube 40
Pump Injector 45
Emulsion Tube 66