Carburetor automatic control system in engine

A carburetor automatic control system for an engine, comprising:

• a choke valve disposed in an intake passage of a carburetor;
• a throttle valve disposed in said intake passage at a position downstream from said choke valve;
• a temperature-sensitive operating device operatively connected with said choke valve for operating said choke valve, wherein said choke valve is opened in correspondence with an increase in engine temperature;
• a governor operatively connected with said throttle valve for opening and closing said throttle valve to maintain a present rotational speed of the engine, wherein said governor includes,
• (a) an electric actuator opening and closing said throttle valve over a range from an idling open degree to a fully open degree, and
• (b) an electronic control unit for controlling said electric actuator to open and close said throttle valve, such that the rotational speed of the engine is maintained at the preset rotational speed;
• and
• a relief mechanism interposed between said choke valve and said temperature-sensitive operating device, said relief mechanism opening said choke valve in response to an intake vacuum pressure within the intake passage of the engine, when the engine is in a cold state, and said choke valve is in a closed state.