Carburetor having an electrically assisted choke valve

Carburetor for internal combustion engine having a body defining an intake duct and an automatic starting device comprising:

• a choke valve located in said duct and arranged to be biased toward opening by an air flow in said intake duct,
• means responsive to the temperature of an engine fed by the carburetor for biasing said choke valve toward closure as long as said temperature is lower than a predetermined limit value,
• an electrically controlled movable stop member having at least one active position in which it permits complete closure of the choke valve and a rest position in which it prevents closing movement of the choke valve beyond a predetermined position,
• first means having at least an active position allowing complete closure of the choke valve and a rest position in which they prevent closing of the choke beyond a predetermined position, and
• second means operatively associated with the first means to maintain said first means in active position and arranged to be inhibited and to leave said first means in said rest position after a sequence including operation of the engine from cold for a period greater than a first predetermined threshold value, then rest condition of the engine for a period less than a second predetermined threshold value.