A method for operating the two stroke engine provides that the fuel valve is controlled after the starting process in at least a quasi-steady state such that, on the basis of uninterruptedly successive blocks of successive revolutions of the crankshaft, the fuel valve is opened and closed exactly once within each block. Each block includes from two to twenty revolutions of the crankshaft. The fuel valve is opened over a crankshaft angle (α) of more than 360° within one block in at least one operating state. A control device is provided for controlling the fuel valve. A quasi-steady state of the two stroke engine is a state in which the throttle element is adjusted by less than 10% of the maximum adjustment of the throttle element over a crankshaft angle (α) of 360°.

An internal combustion engine includes an engine block including a cylinder a piston positioned within the cylinder and configured to reciprocate in the cylinder, an electronic throttle control system comprising a motor and a throttle plate, a fuel system for supplying a controlled amount of fuel to the cylinder including a fuel injector, and an engine control unit coupled to the fuel system and the electronic throttle control system. The engine control unit is configured to determine engine speed data comprising a current engine speed, a previous engine speed, and a desired engine speed and control a fuel injection duration based on the engine speed data.

An engine including an engine block having a cylinder defining a front of the engine, a blower housing coupled to the engine block and defining a hot half and a cool half opposite the front half, a starter mount assembly coupled to the blower housing and positioned within the cool half, an electric starter motor retained by the starter mount assembly, and a battery mounted to the blower housing and positioned in the cool half. The battery is electrically coupled to the electric starter motor.

An engine including an engine block having a cylinder defining a front of the engine, a blower housing coupled to the engine block and defining a hot half and a cool half opposite the front half, a starter mount assembly coupled to the blower housing and positioned within the cool half, an electric starter motor retained by the starter mount assembly, and a battery mounted to the blower housing and positioned in the cool half. The battery is electrically coupled to the electric starter motor.

An internal combustion engine includes an engine block, a blower housing configured to direct cooling air to the engine block, an electric starting system, and a crankshaft configured to rotate about a crankshaft axis. The electric starting system includes an electric motor and an energy storage device located within the blower housing. The energy storage device is electrically coupled to the electric motor to power the electric motor. When the starter motor is activated, the electric starting system rotates the crankshaft to rotate the engine for starting.

A two-stroke combustion engine comprising a user-operated throttle control, an adjustable valve arranged to control one or more air intakes of the combustion engine, and a control unit arranged to control a state of the adjustable valve, wherein the combustion engine is arranged to operate in a first idle mode at an idle engine speed below a clutch engagement engine speed when the user-operated throttle control is not engaged, wherein the combustion engine is arranged to operate in a second idle mode at a target engine speed above the clutch engagement engine speed when the user-operated throttle control is engaged and when the engine is not subject to an external load, the control unit being arranged to control the state of the adjustable valve to maintain engine speed at the target engine speed when the engine operates in the second idle mode.

A two-stroke combustion engine comprising a user-operated throttle control, an adjustable valve arranged to control one or more air intakes of the combustion engine, and a control unit arranged to control a state of the adjustable valve, wherein the combustion engine is arranged to operate in a first idle mode at an idle engine speed below a clutch engagement engine speed when the user-operated throttle control is not engaged, wherein the combustion engine is arranged to operate in a second idle mode at a target engine speed above the clutch engagement engine speed when the user-operated throttle control is engaged and when the engine is not subject to an external load, the control unit being arranged to control the state of the adjustable valve to maintain engine speed at the target engine speed when the engine operates in the second idle mode.

A hand-held power tool comprising an internal combustion engine (4), a working tool (6), a centrifugal clutch (8), and a control system (10) is disclosed. The engine (4) has a clutch-in speed, above which the engine (4) drives the working tool (6). The control system (10) comprises a rotation speed sensor (12), and a speed limitation controller (14), which is configured to limit an engine speed at a limitation speed below the clutch-in speed. It is active or activated during a starting procedure of the internal combustion engine (4). The control system (10) is configured to deactivate the speed limitation controller (14) upon sensing at least one acceleration at a level above the limitation speed and sensing at least one deceleration at a level above the limitation speed, such that the engine (4) is rotatable above the limitation speed to drive the working tool (6).

In at least some implementations, an auxiliary power supply in an ignition system for a light-duty combustion engine includes a first auxiliary winding and a second auxiliary winding coupled in parallel with the first auxiliary winding such that both windings are arranged to provide power to an auxiliary load. The first auxiliary winding may include a greater number of turns than the second auxiliary winding. A ratio of the number of turns in the first auxiliary winding to the number of turns in the second auxiliary winding may be between 1.5:1 and 10:1, the first auxiliary coil and the second auxiliary coil may have between 50 and 2,000 turns, and the first auxiliary coil and the second auxiliary coil are formed from wire between 25 and 45 gauge.

An internal combustion engine includes an engine block including a cylinder, a piston positioned within the cylinder and configured to reciprocate in the cylinder, an electronic throttle control system including a motor and a throttle plate, an air flow sensor configured to detect an air mass flow rate, a fuel system for supplying a controlled amount of fuel to the cylinder including a fuel injector, and an engine control unit coupled to the fuel system and the electronic throttle control system. The engine control unit is configured to determine engine speed data including a current engine speed, a previous engine speed, and a desired engine speed, control a fuel injection duration based on the engine speed data, determine air-fuel ratio data comprising a current air-fuel ratio and a desired air-fuel ratio, and control a throttle plate position based on the air-fuel ratio data.