Abstract: A tool for gauging and adjusting an electrode gap of a spark plug, the spark plug having a center electrode and a side electrode, the side electrode having a free end and a mounted end, with a bend between the two ends. The tool includes an elongated scale portion of substantially constant thickness, having scale indicia on at least one side thereof and an inclined gauge portion extending along at least one side of the scale portion which has a progressively increasing thickness beginning near one end with the thickness of the inclined portion being indicated by the indicia on the scale portion.

Abstract: Disclosed herein is a multiple spark circuit for use with a capacitor discharge ignition system including a current supply, a charge capacitor, an ignition coil primary winding, and an ignition timing SCR. The multiple spark circuit includes a charge reservoir capacitor connected to the current supply, a restrike circuit subject to the timing SCR, and to the voltage and discharge current of the charge capacitor, for allowing repeated charging and discharging of the charge capacitor to produce multiple ignition sparks at each ignition timing point, and a charge interrupt circuit, subject to the restrike circuit, for allowing repeated charging of charge capacitor by the charge reservoir capacitor at each ignition timing point. The restrike circuit preferably comprises a thyristor connected to the timing SCR and charge capacitor, and a zener diode connected to the thyristor gate and anode to render the thyristor conductive when the charge capacitor voltage exceeds a predetermined upper limit.

Abstract: Disclosed herein is a capacitor discharge ignition system including a U-shaped magnetic core having a pair of legs, and a rotatable member including a magnet having arcuately spaced first and second pole shoes located for movement past the core legs, the second pole shoe having a length greater than the distance between the core legs and trailing the first pole shoe relative to a normal direction of rotation of the rotatable member.