Disclosed is a method for determining a need for changing a spark plug of a combustion engine, comprising the following steps: monitoring a current flowing through the spark plug, analyzing the current and thereby determine a time interval that is indicative for the time between application of a voltage to the spark plug and formation of an arc discharge between electrodes of the spark plug, creating a signal indicative of the need to change the spark plug if the duration of the determined time interval is outside predefined bounds.

Systems and methods for operating an engine that may be rotated by an electric machine during engine starting are described. In one example, an amount of electric current that is available to rotate the engine via the electric machine may be adjusted in response to an indication that a vehicle that includes the engine may be parked in a geographical area that may be flooded.

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 internal combustion engine control apparatus includes: an ignition coil including a primary coil and a secondary coil that are magnetically coupled to each other; a first switch element for turning on and off a current to the primary coil; and a spark plug, for igniting an air-fuel mixture in an internal combustion engine by using a spark discharge caused by switching the first switch element from the ON state to the OFF state. The internal combustion engine control apparatus is configured to: determine occurrence of one of an abnormality in a discharge voltage and a misfire of the spark plug, when the calculated time duration in which a voltage of the primary coil after the switching of the first switch element from the ON state to the OFF state is above a predetermined comparison reference voltage does not fall within an allowable range.

An internal combustion engine control apparatus includes: an ignition coil including a primary coil and a secondary coil that are magnetically coupled to each other; a first switch element for turning on and off a current to the primary coil; and a spark plug, for igniting an air-fuel mixture in an internal combustion engine by using a spark discharge caused by switching the first switch element from the ON state to the OFF state. The internal combustion engine control apparatus is configured to: determine occurrence of one of an abnormality in a discharge voltage and a misfire of the spark plug, when the calculated time duration in which a voltage of the primary coil after the switching of the first switch element from the ON state to the OFF state is above a predetermined comparison reference voltage does not fall within an allowable range.

Methods and systems are provided for an internal combustion engine having at least one combustion chamber for burning a fuel mixture and a spark plug for performing spark ignition of the fuel mixture in the combustion chamber. The spark plug includes electrodes for generating an ignition spark at a location within the combustion chamber. Furthermore, the internal combustion engine includes an adjustment device for reducing a distance between the location of the ignition spark and an edge of the combustion chamber in the case of an increase in temperature of the internal combustion engine during operation.

Methods and systems are provided for an internal combustion engine having at least one combustion chamber for burning a fuel mixture and a spark plug for performing spark ignition of the fuel mixture in the combustion chamber. The spark plug includes electrodes for generating an ignition spark at a location within the combustion chamber. Furthermore, the internal combustion engine includes an adjustment device for reducing a distance between the location of the ignition spark and an edge of the combustion chamber in the case of an increase in temperature of the internal combustion engine during operation.

Methods, systems, and computer program products are provided for controlling an internal combustion that comprises a cylinder having a space arranged to receive air and fuel, a piston disposed in the cylinder, and a crankcase being in fluid communication with the cylinder. The method comprises determining an uncontrolled behavior due to fluid flow between said crankcase and said cylinder space and combustion of such fluid, which entails: determining whether a powertrain of the vehicle is disengaged; determining whether the engine speed is increasing; and determining whether said cylinder space is receiving fuel. The method further comprises determining that an uncontrolled behavior is occurring if the conditions that: said powertrain is disengaged, the engine speed is increasing and said cylinder space is not receiving any fuel, are fulfilled.

Methods, systems, and computer program products are provided for controlling an internal combustion that comprises a cylinder having a space arranged to receive air and fuel, a piston disposed in the cylinder, and a crankcase being in fluid communication with the cylinder. The method comprises determining an uncontrolled behavior due to fluid flow between said crankcase and said cylinder space and combustion of such fluid, which entails: determining whether a powertrain of the vehicle is disengaged; determining whether the engine speed is increasing; and determining whether said cylinder space is receiving fuel. The method further comprises determining that an uncontrolled behavior is occurring if the conditions that: said powertrain is disengaged, the engine speed is increasing and said cylinder space is not receiving any fuel, are fulfilled.

A system for interrupting ignition is disclosed. Specific implementations of ignition interrupters may include a first conductive tab configured to couple to a spark plug; a second conductive tab configured to couple to a spark plug wire; a first tab holder coupled with the first conductive tab; a second tab holder coupled with the second conductive tab, where the second conductive tab overlaps with the first conductive tab; a sled positioned perpendicularly to a plane of the first conductive tab and the second conductive tab, the sled coupled between the first conductive tab and the second conductive tab; a first spring coupled to the sled; and a second spring coupled to the sled; where the sled may be configured to move to an open position in the gap between the first conductive tab and the second conductive tab, decompressing the first spring and the second spring.