Malossi with fact manufactured this carburettor Dell' orto which has an active venturi for a better filling of the engine.
According to most international rules, you do not have the right to use carburettors larger than 19mm, from where the interest of this model.
CAUTION!!! This carbu is especially intended for the race, it did not arrive of oil nor of depression, you will have thus to install a manual gasoline tap and to make your mixture yourself
Has to see too :
Dell Orto | Set Gicleur Dell Orto M5 et M6 | Consult |