A combination lever for a carburetor is an integrated shutoff lever and fuel valve. The combination lever includes a longitudinal portion for a handle and a cylindrical portion including a fuel path for the fuel valve. A carburetor casing is shaped to form a valve chamber and a carburetor chamber. The valve chamber supports the cylindrical portion. A directional cavity formed in the cylindrical portion of the combination lever regulates a flow of fuel to the carburetor chamber according to a rotation of the combination lever. At one position the directional cavity opens the fuel path so that fuel flows into the carburetor chamber. At another position the directional cavity closes the fuel path so that the flow of fuel is blocked. The combination lever may also include an abutment portion to engage a switch for completing an electrical shutoff path to an engine coupled to the carburetor.

An electronic circuit (101) for controlling a spark of a spark plug (SP1) in a capacitor discharge ignition system (100) for a combustion engine. The electronic circuit (101) comprises an ignition coil (110) dimensioned and configured to provide current to the spark plug (SP1), an ignition capacitor (C1) dimensioned and configured to supply energy to the primary winding (L1), an voltage source (130) dimensioned and configured to supply energy to at least one of the ignition capacitor (C1) and the primary winding (L1), a first switch (SW1) connected to the first primary terminal (TL1) and the first source terminal (TS1), a second switch (SW2) connected to the second capacitor terminal (TC2) and the second source terminal (TS2), and a third switch (SW3) connected to the second capacitor terminal (TC2) and the first source terminal (TS1). A capacitor discharge ignition system (100) including the electronic circuit (101) and a combustion engine including the capacitor discharge ignition system (100).

An electronic circuit (101) for controlling a spark of a spark plug (SP1) in a capacitor discharge ignition system (100) for a combustion engine. The electronic circuit (101) comprises an ignition coil (110) dimensioned and configured to provide current to the spark plug (SP1), an ignition capacitor (C1) dimensioned and configured to supply energy to the primary winding (L1), an voltage source (130) dimensioned and configured to supply energy to at least one of the ignition capacitor (C1) and the primary winding (L1), a first switch (SW1) connected to the first primary terminal (TL1) and the first source terminal (TS1), a second switch (SW2) connected to the second capacitor terminal (TC2) and the second source terminal (TS2), and a third switch (SW3) connected to the second capacitor terminal (TC2) and the first source terminal (TS1). A capacitor discharge ignition system (100) including the electronic circuit (101) and a combustion engine including the capacitor discharge ignition system (100).

There is provided with a driving machine capable of easily performing switching from a power saving mode to an engine drivable mode. A driving machine comprises an engine; a battery; an operation unit including an emergency stop switch that stops the engine; and a control unit having operation modes, the operation modes including a normal mode in which the engine is drivable and a power saving mode in which the engine is not drivable and a power consumption amount of the battery is suppressed to be smaller than a power consumption amount of the battery in the normal mode, wherein the control unit switches from the power saving mode to the normal mode based on an input of the emergency stop switch when the operation mode is the power saving mode.

An engine control device includes an electronic control unit. The electronic control unit is configured to perform a spark discharge with an ignition plug for each cylinder by cutting off energization after elapse of a predetermined period from start of energization to an ignition coil for each cylinder of the engine, to stop the spark discharge caused by the ignition plug for each cylinder after supply of fuel to the engine is stopped when operation of the engine is stopped, and to control an ignition plug so as to stop the spark discharge caused by the ignition plug from a cylinder after a rotation speed of a crankshaft decreases gradually and the rotation speed of the crankshaft reaches a preset threshold value or less, after the stop of the supply of fuel to the engine.

An engine control device includes an electronic control unit. The electronic control unit is configured to perform a spark discharge with an ignition plug for each cylinder by cutting off energization after elapse of a predetermined period from start of energization to an ignition coil for each cylinder of the engine, to stop the spark discharge caused by the ignition plug for each cylinder after supply of fuel to the engine is stopped when operation of the engine is stopped, and to control an ignition plug so as to stop the spark discharge caused by the ignition plug from a cylinder after a rotation speed of a crankshaft decreases gradually and the rotation speed of the crankshaft reaches a preset threshold value or less, after the stop of the supply of fuel to the engine.

A method for controlling the operation of a spark ignition internal combustion engine is described. The engine includes: a combustion chamber, an intake duct for placing the combustion chamber in communication with the external, a throttle valve arranged inside the intake duct, a carburetor for introducing fuel into the intake duct to form an air/fuel mixture to be intaken into the combustion chamber, and a spark plug arranged inside the combustion chamber to generate a spark for igniting the combustion of the air/fuel mixture. The method includes: monitoring the opening degree of the throttle valve; monitoring the speed of the engine, preventing the spark plug from generating the spark, if the opening degree of the throttle valve drops below a first opening degree threshold value and the speed of the engine is greater than a first engine speed threshold value.

A handheld work apparatus has a combustion engine, a pull-rope starter, and a stop button for switching off the combustion engine. A throttle element is arranged in an intake channel of the combustion engine. The work apparatus has a control device for activating a spark plug and a fuel valve. The control device has a starting mode wherein the combustion engine can be started via the pull-rope starter, and an operating mode wherein the operator can adjust the throttle to vary the rotational speed (n) of the combustion engine. The operating and starting mode differ in terms of the control of ignition time and fuel quantity to be supplied. When the combustion engine is started from the switched-off state, the control device is automatically in starting mode, such that after the combustion engine is switched off, the work apparatus is immediately ready for restarting via the pull-rope starter.

A method for controlling the operation of a spark ignition internal combustion engine is described. The engine includes: a combustion chamber, an intake duct for placing the combustion chamber in communication with the external, a throttle valve arranged inside the intake duct, a carburetor for introducing fuel into the intake duct to form an air/fuel mixture to be intaken into the combustion chamber, and a spark plug arranged inside the combustion chamber to generate a spark for igniting the combustion of the air/fuel mixture. The method includes: monitoring the opening degree of the throttle valve; monitoring the speed of the engine, preventing the spark plug from generating the spark, if the opening degree of the throttle valve drops below a first opening degree threshold value and the speed of the engine is greater than a first engine speed threshold value.

An engine control device includes an electronic control unit. The electronic control unit is configured to perform a spark discharge with an ignition plug for each cylinder by cutting off energization after elapse of a predetermined period from start of energization to an ignition coil for each cylinder of the engine, to stop the spark discharge caused by the ignition plug for each cylinder after supply of fuel to the engine is stopped when operation of the engine is stopped, and to control an ignition plug so as to stop the spark discharge caused by the ignition plug from a cylinder after a rotation speed of a crankshaft decreases gradually and the rotation speed of the crankshaft reaches a preset threshold value or less, after the stop of the supply of fuel to the engine.