Engine ignition timing device

A method for timing an engine having a timing port through which a timing mark indicative of a position of a movable member of the engine can be seen, the method comprising:

• securing a variable reluctance sensor proximate the timing port;
• sensing the presence of the timing mark of the engine with the variable reluctance sensor and providing a timing mark signal as a function thereof;
• sensing an occurrence of an ignition spark and providing an ignition signal as a function thereof;
• filtering ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder and providing a filtered ignition signal being indicative of only the ignition sparks of compression strokes;
• generating a delayed signal having a selected delay from the filtered ignition signal;
• comparing the timing mark signal to the ignition signal and providing an output signal indicative of substantial simultaneous occurrence of the timing mark signal and the delayed signal;
• and
• operating an indicator as a function of the output signal.

An ignition timing device for timing an engine having a timing port and a timing mark indicative of a position of a movable member, the ignition timing device comprising:

• a sensor adapted to be secured in the timing port to provide a timing mark signal indicative of presence of the timing mark;
• an ignition sensor adapted to provide an ignition signal indicative of the occurrence of an ignition spark;
• filtering means for receiving the ignition signal and filtering ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder as a function of a voltage of the ignition signal to provide a filtered ignition signal;
• and
• a comparator receiving the timing mark signal and the filtered ignition signal, the comparator providing an output signal indicative of relative occurrence of the timing mark signal and the filtered ignition signal.