A method for safely capturing an engine RPM threshold in a spark-ignition internal combustion engines which may exceed the maximum safe unloaded RPM for that engine. Typical engines having a safe RPM high speed redline when coupled to a load, and a reduced RPM redline when decoupled and unloaded, can be set to activate ancillary equipment at a high redline, engine loaded RPM by deriving and processing data from the engine at a low, unloaded reduced RPM speed. The method requires operator reference to an existing OEM or after-market tachometer which enables the user to set a low RPM reference point while the engine is unloaded and running at a slow RPM. Raw data from the latter variable RPM threshold selected by a user is safely captured while the engine is operating unloaded, and a higher RPM threshold is calculated and set from the raw data. The higher RPM threshold may exceed the maximum safe unloaded RPM for said engine.

An ignition system of a combustion engine has a start-up adjustment curve with a maximum rotational speed, an operating adjustment curve and a switch-over device for switching between curves. The start-up adjustment curve is selected in the case of a start-up of the combustion engine. A rotational speed curve is divided into adjacent cycles. The start of the first cycle is the point in time of the second ignition after the start-up and the start of the subsequent cycles is in each case the point in time of ignition at which the rotational speed is less than in the case of the subsequent point in time of ignition. The criterion for switching to the operating adjustment curve is whether the average of the rotational speeds of successive cycles differs by less than a first tolerance value.

An ignition control device according to one embodiment of the present invention is configured to, based on a pulse signal to be induced in an ignition coil in accordance with rotation of an internal combustion engine, cause a voltage to be supplied to an ignition plug included in the internal combustion engine, to be generated in the ignition coil. The ignition control device includes: a switching element configured to energize the ignition coil; a biasing unit configured to bias control terminals of the switching element so that the switching element is turned on when the pulse signal is induced; a state detecting unit configured to detect a biased state of the switching element; and a control unit configured to set a timing for controlling de-energization of the ignition coil in response to a result of detection performed by the state detecting unit, and to control the switching element to be turned off in accordance with the timing.

The engine starting device for stopping, when an engine automatic stop condition is satisfied, fuel injection to the engine to automatically stop the engine, and for thereafter restarting the engine when an engine restart condition is satisfied, includes: a ring gear coupled to a crankshaft of the engine; a starter motor rotated by a current supply; a pinion gear for transmitting the rotation of the starter motor to the ring gear; a pinion gear moving part for moving the pinion gear toward the ring gear by a current supply, thereby meshing the pinion gear with the ring gear; and a fuel injection control part for restarting the fuel injection so that combustion is generated in a predetermined compression cylinder after the engine restart condition is satisfied and after the pinion gear moving part starts the movement of the pinion gear.