Abstract: An internal combustion engine has a cylinder in which a combustion chamber, bounded on one side by a reciprocating piston, is formed. The piston drives a crankshaft rotatably mounted in a crank casing. The internal combustion engine has an inlet opening for combustion air into the crank casing, and an outlet opening out of the combustion chamber. The internal combustion engine has at least one overflow duct which connects the crank casing interior to the combustion chamber. The internal combustion engine has a crank casing pressure sensor for measuring the crank casing pressure, a device for determining the rotational position of the crankshaft, and an evaluation device which evaluates the measurements of the crank casing pressure sensor. A method for operating the internal combustion engine is provided where the ambient pressure is determined using the crank casing pressure measured by the crank casing pressure sensor.

Abstract: A combustion engine has a fuel supply unit, an ignition unit and a controller controlling the amount of fuel and the ignition time. An adjustable throttle element controlling the amount of combustion air to the engine and an adjustable idling stop for the throttle element are provided. The controller includes a regulating unit regulating the rotational speed of the motor to a set-point rotational speed (nsoll) when idling. To adjust the idling stop, the regulating unit is switched off when idling. A diagnostic unit switches off the regulating unit. A method for adjusting a combustion engines provides that the regulating unit is switched off, the amount of fuel supplied is adjusted during idling and a rotational speed is evaluated, and that on the basis of the rotational speed value, it is determined how the idling stop is to be adjusted to reach a set-point rotational speed maximum (nsollmax).

Abstract: An internal combustion engine of a hand-held power tool has a crankcase having a circumferential wall extending in a circumferential direction of the crankcase. A crankshaft is supported so as to be rotatable about an axis of rotation within the crankcase. At least one transfer passage extends from the crankcase into the cylinder of the engine, wherein the transfer passage has an inlet port at the crankcase. At least one fuel retaining device is disposed on the circumferential wall of the crankcase. A radial direction, starting at the axis of rotation of the crankshaft and extending outwardly, extends through the at least one fuel retaining device. The at least one fuel retaining device has a depth in the radial direction and a length in the circumferential direction. The at least one fuel retaining device, relative to the radial direction, has an asymmetric cross-section in the circumferential direction.

Abstract: A two-stroke engine (1) has a cylinder (2) defining a combustion chamber (3) delimited by a piston (5). The piston (5) drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (17) at at least one position of the piston. The two-stroke engine has an inlet (11) into the crankcase (4) and an outlet (19) from the combustion chamber. There is an arrangement to supply fuel, a control, and a device to determine the crankcase pressure (pKGH). A method to operate the two-stroke engine (1) includes determining the crankcase pressure (pKGH) during every engine cycle. The fluctuation in the crankcase pressure (pKGH) is determined and the fluctuation is compared to a limit value (?plimit) to determine whether a combustion occurs during every engine cycle. In this way, a determination can be reliably made as to whether the two-stroke engine is running in a four-stroke mode.

Abstract: For operating an internal combustion engine with a combustion chamber delimited by a piston driving a crankshaft in a crankcase, with a device for supplying fuel, an ignition device, and an electronic control unit, wherein a correlation between a power output of the internal combustion engine and a lambda value in the combustion chamber is defined by a power output curve that has a first ascending branch, a maximum, and a second descending branch where the lambda value is smaller than 1, the position of an operating point of the internal combustion engine is determined by adjusting the ignition timing to an adjusted ignition timing and evaluating the engine speed reaction caused by the adjusted ignition timing. The supplied fuel quantity is changed as a function of the determined position of the operating point when the determined position of the operating point is not a desired operating point.

Abstract: An internal combustion engine has a cylinder in which a combustion chamber, bounded on one side by a reciprocating piston, is formed. The piston drives a crankshaft rotatably mounted in a crank casing. The internal combustion engine has an inlet opening for combustion air into the crank casing, and an outlet opening out of the combustion chamber. The internal combustion engine has at least one overflow duct which connects the crank casing interior to the combustion chamber. The internal combustion engine has a crank casing pressure sensor for measuring the crank casing pressure, a device for determining the rotational position of the crankshaft, and an evaluation device which evaluates the measurements of the crank casing pressure sensor. A method for operating the internal combustion engine is provided where the ambient pressure is determined using the crank casing pressure measured by the crank casing pressure sensor.

Abstract: A combustion engine has a fuel supply unit, an ignition unit and a controller controlling the amount of fuel and the ignition time. An adjustable throttle element controlling the amount of combustion air to the engine and an adjustable idling stop for the throttle element are provided. The controller includes a regulating unit regulating the rotational speed of the motor to a set-point rotational speed (nsoll) when idling. To adjust the idling stop, the regulating unit is switched off when idling. A diagnostic unit switches off the regulating unit. A method for adjusting a combustion engines provides that the regulating unit is switched off, the amount of fuel supplied is adjusted during idling and a rotational speed is evaluated, and that on the basis of the rotational speed value, it is determined how the idling stop is to be adjusted to reach a set-point rotational speed maximum (nsollmax).

Abstract: For operating an internal combustion engine with a combustion chamber delimited by a piston driving a crankshaft in a crankcase, with a device for supplying fuel, an ignition device, and an electronic control unit, wherein a correlation between a power output of the internal combustion engine and a lambda value in the combustion chamber is defined by a power output curve that has a first ascending branch, a maximum, and a second descending branch where the lambda value is smaller than 1, the position of an operating point of the internal combustion engine is determined by adjusting the ignition timing to an adjusted ignition timing and evaluating the engine speed reaction caused by the adjusted ignition timing. The supplied fuel quantity is changed as a function of the determined position of the operating point when the determined position of the operating point is not a desired operating point.

Abstract: A two-stroke engine (1) has a cylinder (2) defining a combustion chamber (3) delimited by a piston (5). The piston (5) drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (17) at at least one position of the piston. The two-stroke engine has an inlet (11) into the crankcase (4) and an outlet (19) from the combustion chamber. There is an arrangement to supply fuel, a control, and a device to determine the crankcase pressure (pKGH). A method to operate the two-stroke engine (1) includes determining the crankcase pressure (pKGH) during every engine cycle. The fluctuation in the crankcase pressure (pKGH) is determined and the fluctuation is compared to a limit value (?plimit) to determine whether a combustion occurs during every engine cycle. In this way, a determination can be reliably made as to whether the two-stroke engine is running in a four-stroke mode.

Abstract: A carburetor of an internal combustion engine for operating a manually-guided implement, including an intake channel having a venturi section for combustion air, a fuel channel that opens into the intake channel via a fuel opening, and an accelerator pump that is in flow-conducting communication with the fuel opening. During operation of the carburetor, the fuel channel is adapted to have fuel flow continuously therethrough. The fuel channel is guided through a pump chamber of the accelerator pump.

Abstract: A carburetor of an internal combustion engine for operating a manually-guided implement, comprising an intake channel having a venturi section for combustion air, a fuel channel that opens into the intake channel via a fuel opening, and an accelerator pump that is in flow-conducting communication with the fuel opening. During operation of the carburetor, the fuel channel is adapted to have fuel flow continuously therethrough. The fuel channel is guided through a pump chamber of the accelerator pump.