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Years of experience lead us to work almost exclusively with Mikuni carburetors (see Onlineshop). Their technical standard and the performance are superior to the Dellorto Carburetors. The jetting of Mikuni carburetors is much simpler and more precise than the Dellorto flat slide or cylindrical slide carburetors.

Carburetor Size
The selection of the correct size of a carburetor is not always simple. There are two factors that determine the size needed: Displacement and nominal rpm.

Example: a 125 ccm motor that has its max power at 6,000 rpm is not putting through as much air as a 350 ccm motor that has its max power at 10,000 rpm.

Carburetors need a sufficient speed of gas passing through to be able to form a good gas-air mixture. If comparing a 30mm carburetor with a 38mm carburetor on the same motor, the 30mm carburetor will have a much higher velocity of the air passing through: as a result the venturi effect (vacuum that pulls the gas into the air stream) is much more effective in the 30mm carburetor. The suction and atomization of the gas works much better at low rpm with the smaller carburetor but not worse at higher rpm.

The crucial factor is not the diameter of the carburetor, but the area. A 35mm carburetor is twice as large as a 25mm carburetor (25 mm = 490 sqmm, 35 mm = 961 sqmm).

We achieve very good results with a 30mm Mikuni carburetor (see Onlineshop) on Lambretta with ported standard cylinder and AF Clubman exhaust. Yet with a 27mm Mikuni carburetor (see Onlineshop) we have slightly better performance at lower rpm. Hence we use the 27mm Mikuni.

The Mikuni carburetors offer better response and performance. They atomize the gas finer. The following types are well tried:

(see Onlineshop)

27 mm with Power Jet

30 mm with Power Jet

35 mm without Power Jet

38 mm with Power Jet

The Power Jet System is not a typical "Injection", but it richens the fuel air mixture at full throttle and high gas velocity (high rpm). Only then gas is sucked through a channel from the float bowl and is then fed into the air stream. This creates a better fuel air mixture and prevents lean condition at full throttle.