This is a genuine Mikuni VM20-151!
Originally installed on a Zündapp KS50 WC
Equipped with
Main jet: #65(4/042-strl)
Low-speed jet: #30(VM22/210-strl)
Throttle needle: 4DH11 (J8-)
Needle nozzle: O6 (145-size)
Throttle: 2.5 (VM20/565-cut)
Needle valve: 1.5 (VM15/172-size)
Air nozzle: fixed
Physical dimensions
Motor connection dimensions: 26 mm (clamp mount)
Outer diameter at air chamber: 35 mm
Total length: 67 mm
From center to highest point: 60 mm
From center to lowest point: 55 mm
Idle screw: left side
Float height: 22 mm.
Air screw: 1.5 turns
Mikuni advises not to tilt the carburettors more than 15°-20°