Ignition timing control method for internal combustion engines

Abstract

An ignition timing control method for an internal combustion engine wherein a plurality of correction values for ignition timing are stored in memory means beforehand as a function of an output voltage from a variable voltage creating means which is humanly adjustable and the rotational speed of the engine. The output voltage from the variable voltage creating means and the rotational speed of the engine are detected, and one of the correction values is read, which corresponds to the detected output voltage and the detected rotational speed of the engine. Then, the ignition timing is corrected by the use of the read one correction value. Further, a value of a parameter indicative of load on the engine is detected, and the ignition timing control is executed when the detected value of the parameter is above a predetermined value. Alternatively, in place of the correction values, address values are stored in memory means. One of the address values is read, which corresponds to the detected output voltage and converted to a numerical value in the number system with a predetermined number as the base. The figures of the numerical value correspond to respective regions of the engine rotational speed. A correction value for correcting the ignition timing is determined in accordance with one of the figures of the numerical value corresponding to the region of the engine rotational speed in which the engine is detected to be operating.