Patent ID: 7213555

Claim:
An automatic choke for controlling an opening degree of a choke valve provided in an intake passage of an engine upon start of the engine, comprising; a stepping motor for controlling the opening degree of the choke valve, wherein the choke valve is driven to a fully closed side for initializing the stepping motor when a power source for starting the engine is turned on, wherein the opening degree of the choke valve upon start of engine is determined on the basis of a temperature information representing an engine temperature upon start of engine, a time until releasing the choke corresponding to fully opening the choke valve from the opening degree of the choke valve upon start of the engine is determined on the basis of the temperature information, wherein the engine is controlled to settle at a predetermined reference speed, and wherein a time until releasing the choke depends on the reference speed, and is determined to be shorter when the reference speed is higher, and longer when the reference speed is lower.