My engine only uses one primary trigger mounted on the perimeter of the flywheel picked up by a VR sensor.

Currently I only have a 'wordy' description of the trigger which is as follows:

Forty four evenly spaced steel teeth are set into the periphary of the flywheel. Two teeth are then removed at each of the positions 90 BTDC and 90 BBDC. The 40 teeth that remain include two double teeth set just before the space where the smaller teeth were removed.