Patent ID: 8733322

Claim:
An air-fuel ratio control device for a carburetor, comprising: a choke valve arranged in an intake path of an internal combustion engine; a throttle valve arranged in the intake path on a downstream side of the choke valve; a first stepper motor driving the choke valve to adjust an opening degree of the choke valve; a second stepper motor driving the throttle valve to adjust an opening degree of the throttle valve; and a controller which controls the opening degree of the choke valve in accordance with a change of a rotation speed of the internal combustion engine based on the opening degree of the throttle valve, and, when the rotation speed of the internal combustion engine is constant, controls the opening degree of the choke valve based on a map which determines the opening degree of the choke valve from load of the internal combustion engine, so as to achieve a desired air-fuel ratio.