PURPOSE: To provide the main air adjusting device for a carburetor, which can keep an optimum air-fuel ratio for a range of a high and a low speed by dividing a pipe for the main air passage of the carburetor into two, and thereby connecting a duty solenoid and an opening solenoid to each of the divided pipes.
CONSTITUTION: A pipe 3 connected to the main air passage 2 of a carburetor 1 is divided into two, a duty solenoid 6 is connected to one of them via a large throttle 4, and a closing solenoid 7 is connected to the other via a small throttle 5. Besides, the pipe 3 connected to the main air passage 2 is divided into two, one of them is connected to the opening solenoid 6 via the small throttle 5, and the other is connected via the large throttle 4 to the opening solenoid 7 and to the duty solenoid 6.
ARAI HIROMITSU