Abstract: In an internal combustion engine electronic ignition system of the type responsive to each of a series of alternating current timing signals of an amplitude directly proportional to engine speed that are induced in the output coil of an electrical generator assembly having at least a rotor member rotated in timed relationship with the engine, the timing signals are overriden by the output signal of a circuit combination that is responsive to a potential level of a predetermined magnitude across the electrical generator assembly output coil to provide an engine speed ignition spark advance within increasing engine speeds greater than a selected value that substantially follows a desired engine speed ignition spark advance curve.