The Dellorto 20.5mm PHVB is typical for 2-stroke Maxi scooters. Depending on the vehicle type, either a Mikuni or such Dellorto is installed in the vehicles at the factory. Mikuni carburettors are usually not that easy to buy or fairly pricey. The PHVB 20.5 is an inexpensive alternative for a defective original carburettor. Moreover, a factory fitted Mikuni carburettor can be easily exchanged for these Dellorto carbs. Generally, the jetting has to be adjusted. This Dellorto is supplied with an E-Choke. Choke: E-Choke (included) oil port connection engine: 29mm connection Air filter side: 41mm main jet: M6 # 83 pilot jet: M5 # H45 Float: 13700.1 carburettor slide: 40 (metal version) needle choice: M6