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 drive system may include an internal combustion engine and an expander operated via a working medium. A force transmission device may be disposed between a crankcase and the expander. A first seal may be disposed between the expander and the force transmission device and/or a second seal may be disposed between the force transmission device and the crankcase. A crankcase ventilation line may lead from the crankcase into an intake pipe of the internal combustion engine. An air mass sensor may be disposed in the intake pipe. An engine control unit may be in communication with the air mass sensor, the expander, and the internal combustion engine and may be configured to detect a power of the internal combustion engine and an air mass flow of the air mass sensor and may switch off the expander if a power suddenly rises with the air mass flow remaining constant.

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 drive system may include an internal combustion engine and an expander operated via a working medium. A force transmission device may be disposed between a crankcase and the expander. A first seal may be disposed between the expander and the force transmission device and/or a second seal may be disposed between the force transmission device and the crankcase. A crankcase ventilation line may lead from the crankcase into an intake pipe of the internal combustion engine. An air mass sensor may be disposed in the intake pipe. An engine control unit may be in communication with the air mass sensor, the expander, and the internal combustion engine and may be configured to detect a power of the internal combustion engine and an air mass flow of the air mass sensor and may switch off the expander if a power suddenly rises with the air mass flow remaining constant.