A method for synchronizing an internal combustion engine includes: a) a first step of acquiring, by the camshaft sensor, signals corresponding to at least five cam edges x; b) a second step of determining the value, from the camshaft signal, of a first, second and third actual ratio; c) a third step of establishing, for each actual value ratio obtained in b), a list of possible cam edges x by comparing the values of the first, second and third actual ratios, respectively, with a tolerance window corresponding to a value of a first, second or third theoretical ratio for a given cam edge x, each weighted by a tolerance factor k; and d) a fourth step of determining the cam edge x seen by the camshaft sensor, the cam edge actually seen by the sensor corresponding to the cam edge x common to the three lists established in c).

A method for synchronizing an internal combustion engine includes: a) a first step of acquiring, by the camshaft sensor, signals corresponding to at least five cam edges x; b) a second step of determining the value, from the camshaft signal, of a first, second and third actual ratio; c) a third step of establishing, for each actual value ratio obtained in b), a list of possible cam edges x by comparing the values of the first, second and third actual ratios, respectively, with a tolerance window corresponding to a value of a first, second or third theoretical ratio for a given cam edge x, each weighted by a tolerance factor k; and d) a fourth step of determining the cam edge x seen by the camshaft sensor, the cam edge actually seen by the sensor corresponding to the cam edge x common to the three lists established in c).

A detection apparatus for detecting a cam angle of a 4-stroke multi-cylinder engine in which explosion intervals are unequal intervals, includes a detection target member configured to rotate in synchronism with a camshaft, and first and second cam angle sensors configured to detect rotation of the detection target member. The detection target member includes a plurality of first detection target portions arranged, at equal pitches, as many as the number of cylinders of the multi-cylinder engine. The second cam angle sensor is arranged while being shifted in the rotation direction with respect to the first cam angle sensor such that any one of detection signals of the plurality of first detection target portions by the first cam angle sensor and the second cam angle sensor is output at a timing corresponding to each explosion interval.

A method for synchronizing an internal combustion engine includes: a) a first step of acquiring, by the camshaft sensor, signals corresponding to at least five cam edges x; b) a second step of determining the value, from the camshaft signal, of a first, second and third actual ratio; c) a third step of establishing, for each actual value ratio obtained in b), a list of possible cam edges x by comparing the values of the first, second and third actual ratios, respectively, with a tolerance window corresponding to a value of a first, second or third theoretical ratio for a given cam edge x, each weighted by a tolerance factor k; and d) a fourth step of determining the cam edge x seen by the camshaft sensor, the cam edge actually seen by the sensor corresponding to the cam edge x common to the three lists established in c).

A method for synchronizing an internal combustion engine includes: a) a first step of acquiring, by the camshaft sensor, signals corresponding to at least five cam edges x; b) a second step of determining the value, from the camshaft signal, of a first, second and third actual ratio; c) a third step of establishing, for each actual value ratio obtained in b), a list of possible cam edges x by comparing the values of the first, second and third actual ratios, respectively, with a tolerance window corresponding to a value of a first, second or third theoretical ratio for a given cam edge x, each weighted by a tolerance factor k; and d) a fourth step of determining the cam edge x seen by the camshaft sensor, the cam edge actually seen by the sensor corresponding to the cam edge x common to the three lists established in c).

A method for managing start up of a four-stroke engine, the method being performed by a controller communicatively connected to the engine. The method includes determining, using a crankshaft sensor, an angular orientation of the crankshaft, the crankshaft being rotated by a starter motor prior to ignition of the engine; determining, using the crankshaft sensor, at least one engine speed variation as the crankshaft rotates through at least one measurement window; and identifying a working cycle phase of the crankshaft including in response to an absolute value of the at least one engine speed variation being above a threshold, determining that the crankshaft is in an ignition revolution of a two revolution working cycle of the engine in the measurement window, subsequent ignition of the engine being based on determination of the angular orientation and the working cycle phase of the crankshaft.

A capacitive ignition system for an internal combustion engine includes a voltage converter which has two primary terminals and two secondary terminals a primary voltage source has two voltage source terminals (A+, A) which are connected in each instance to one of the primary terminals so that a primary circuit is formed; a switch which is incorporated within the primary circuit and a controller so that the switch can be closed and opened; a first control device constructed to actuate the controller in accordance with an ignition pattern for closing and/or opening; an electrical capacitance (C1, C2) within the primary circuit; and a second control device (25) constructed to maintain constant a voltage rise at the secondary terminals, which occurs in order to reach the ignition voltage, as the ignition energy requirement of an ignition device connected to the secondary terminals changes.

A magneto timing control system is described. The magneto timing control system can include an element configured to adjust tension of one of a first section of a belt and a section of the belt, wherein the belt is in communication with at least one magneto. The tension of the first section of the belt and the second section of the belt control a timing advance and a timing retard of the at least one magneto.

A method for managing start up of a four-stroke engine, the method being performed by a controller communicatively connected to the engine. The method includes determining, using a crankshaft sensor, an angular orientation of the crankshaft, the crankshaft being rotated by a starter motor prior to ignition of the engine; determining, using the crankshaft sensor, at least one engine speed variation as the crankshaft rotates through at least one measurement window; and identifying a working cycle phase of the crankshaft including in response to an absolute value of the at least one engine speed variation being above a threshold, determining that the crankshaft is in an ignition revolution of a two revolution working cycle of the engine in the measurement window, subsequent ignition of the engine being based on determination of the angular orientation and the working cycle phase of the crankshaft.

A magneto timing control system is described. The magneto timing control system can include an element configured to adjust tension of one of a first section of a belt and a section of the belt, wherein the belt is in communication with at least one magneto. The tension of the first section of the belt and the second section of the belt control a timing advance and a timing retard of the at least one magneto.