Systems and methods for operating a spark ignition engine that includes a particulate filter in the engine's exhaust system are described. In one example, a threshold temperature at which the spark ignition engine may be automatically stopped is adjusted according to an amount of soot that is stored in the particulate filter.

An apparatus obtains waveforms representing measurements of a physical characteristic of a machine's operation and performance results of the machine corresponding respectively to the waveforms, each of the performance results being indicative of the machine's performance under conditions at which the measurement represented by the corresponding waveform was made. The apparatus calculates, for each of at least interval associated with each of the waveforms, an influence value that represents a degree of influence of the waveforms on the performance results over the interval.

An apparatus obtains waveforms representing measurements of a physical characteristic of a machine's operation and performance results of the machine corresponding respectively to the waveforms, each of the performance results being indicative of the machine's performance under conditions at which the measurement represented by the corresponding waveform was made. The apparatus calculates, for each of at least interval associated with each of the waveforms, an influence value that represents a degree of influence of the waveforms on the performance results over the interval.

Operating a dual fuel engine system includes igniting a main charge of gaseous fuel in response to combustion of an early pilot shot of liquid fuel and production of a spark. Operating the system also includes covarying a spark timing parameter and a pilot shot delivery parameter, and reducing an error in a phasing of combustion of another main charge based on the covarying of the spark timing parameter and the pilot shot delivery parameter.

An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

Operating a dual fuel engine system includes igniting a main charge of gaseous fuel in response to combustion of an early pilot shot of liquid fuel and production of a spark. Operating the system also includes covarying a spark timing parameter and a pilot shot delivery parameter, and reducing an error in a phasing of combustion of another main charge based on the covarying of the spark timing parameter and the pilot shot delivery parameter.

A prime mover for a lightweight vehicle comprising an internal combustion engine, a starter motor integrally integrated with the internal combustion engine, and a housing for the prime mover. The prime mover additionally comprises a Hall Effect sensor and an prime mover control module structured and operable to communicate with the Hall Effect sensor, determine when operation of the internal combustion engine should cease, and upon the determination that operation of the internal combustion engine should cease, utilize the communication from the Hall Effect sensor to stop the internal combustion engine such that a piston of the internal combustion engine is positioned at between 15 and 25 after bottom-dead-center.

An electronic ignition system for a portable gasoline tool includes a voltage boosting device, a spark plug connected with an output of the voltage boosting device, a DC power source, and a controller electrically connected with the DC power source and connected with the voltage boosting device. The controller controls an ignition voltage and an ignition advance angle. A related portable gasoline tool includes a body, a cylinder located in the body, a piston movable to and fro within the cylinder, a crankshaft co-moved with the piston, and a flywheel located on the body and driven by the crankshaft to rotate.

An electronic ignition system for a portable gasoline tool includes a voltage boosting device, a spark plug connected with an output of the voltage boosting device, a DC power source, and a controller electrically connected with the DC power source and connected with the voltage boosting device. The controller controls an ignition voltage and an ignition advance angle. A related portable gasoline tool includes a body, a cylinder located in the body, a piston movable to and fro within the cylinder, a crankshaft co-moved with the piston, and a flywheel located on the body and driven by the crankshaft to rotate.

An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.