Abstract: A control section starts cranking of an engine with a first opening degree upon detection of a first operation signal, and, if the engine has reached a predetermined number of rotations through a predetermined number of times of the cranking with the first opening degree, the control section starts running of the engine in a first mode corresponding to the first opening degree. If the engine has not reached the predetermined number of rotations through the predetermined number of times of the cranking with the first opening degree, the control section starts cranking with a second opening degree, and, if the engine has reached the predetermined number of rotations through the predetermined number of times of the cranking with the second opening degree, the control section starts running of the engine in a second mode corresponding to the second opening degree.

Abstract: A control section starts cranking of an engine with a first opening degree upon detection of a first operation signal, and, if the engine has reached a predetermined number of rotations through a predetermined number of times of the cranking with the first opening degree, the control section starts running of the engine in a first mode corresponding to the first opening degree. If the engine has not reached the predetermined number of rotations through the predetermined number of times of the cranking with the first opening degree, the control section starts cranking with a second opening degree, and, if the engine has reached the predetermined number of rotations through the predetermined number of times of the cranking with the second opening degree, the control section starts running of the engine in a second mode corresponding to the second opening degree.

Abstract: An electronic control system for a carburetor, includes: a transmission device linked to a valve; an electric actuator for driving the valve; and an electronic control unit for controlling operation of the electric actuator, the electric actuator being disposed between the transmission device and the electronic control unit, The transmission device, the electric actuator and the electronic control unit are housed and held in a casing mounted on the carburetor. A ventilation apparatus which places an interior of the casing in communication with an outside atmosphere relative to the carburetor is connected to the casing.

Abstract: A fuel feed system of an engine is provided with a gas-fuel separating unit for separating oil mist generated in an engine case from air with a labyrinth, and an auto fuel cock is operated by pressure pulsation of the air from which the oil mist is separated by the gas-liquid separating unit. Thus, infiltration of the oil mist into the auto fuel cock is suppressed to the minimum, and a malfunction of the auto fuel cock caused by accumulation of the oil can be prevented. Additionally, a breather passage for feeding the air, from which the oil mist is separated by the gas-liquid separating unit, to a breathing unit is connected the auto fuel cock via a negative pressure tube. Thus, it is unnecessary to provide a specific passage for transmitting the pressure pulsation of the air in the engine case to the auto fuel cock.

Abstract: An electronic control system for a carburetor, includes: a transmission device (24, 25) linked to a valve (7, 8); an electric actuator (20, 21) for driving the valve (7, 8); and an electronic control unit (12a) for controlling operation of the electric actuator (20, 21). The transmission device (24, 25), the electric actuator (20, 21) and the electronic control unit (12a) are housed and held in a casing (10) mounted on the carburetor (C). The ventilation means (72, 74, 74?, 89, 90) for causing an interior of the casing (10) to communicate with the outside is connected to the casing (10). Therefore, it is possible to house the transmission device, the electric actuator and the electronic control unit efficiently in a common casing so as to downsize the electronic control system for a carburetor, and improve durability of the electronic control unit and the electric actuator.

Abstract: A fuel feed system of an engine is provided with a gas-fuel separating unit for separating oil mist generated in an engine case from air with a labyrinth, and an auto fuel cock is operated by pressure pulsation of the air from which the oil mist is separated by the gas-liquid separating unit. Thus, infiltration of the oil mist into the auto fuel cock is suppressed to the minimum, and a malfunction of the auto fuel cock caused by accumulation of the oil can be prevented. Additionally, a breather passage for feeding the air, from which the oil mist is separated by the gas-liquid separating unit, to a breathing unit is connected the auto fuel cock via a negative pressure tube. Thus, it is unnecessary to provide a specific passage for transmitting the pressure pulsation of the air in the engine case to the auto fuel cock.

Abstract: In an electrically-actuated throttle device for a general-purpose engine, supply of current to the throttle motor and choke motor for moving the throttle valve and choke valve is started when cranking is detected after activation (power-up) of the electronic control unit (ECU). In other words, supply of current is not started simultaneously with activation of the ECU but is delayed until cranking is detected. Owing to this configuration, no power of the battery is consumed unnecessarily between power-up and starting of the engine. Decrease in the power supplied to the starter motor is therefore prevented, thereby improving the starting performance of the engine. In addition, even if starting of the engine is not commenced after power-up, the battery is not likely to be excessively discharged.

Abstract: In an electrically-actuated throttle device for a general-purpose engine, supply of current to the throttle motor and choke motor for moving the throttle valve and choke valve is started when cranking is detected after activation (power-up) of the electronic control unit (ECU). In other words, supply of current is not started simultaneously with activation of the ECU but is delayed until cranking is detected. Owing to this configuration, no power of the battery is consumed unnecessarily between power-up and starting of the engine. Decrease in the power supplied to the starter motor is therefore prevented, thereby improving the starting performance of the engine. In addition, even if starting of the engine is not commenced after power-up, the battery is not likely to be excessively discharged.