Can you use one of the old capacitive (Iinductive?) Sears timing light to check for spark on a magneto equipped engine? This would entail having to put a short length of unshielded sparkplug wire in the line for the pickup to sense from? Will the timing light flash when the mag produces a spark? Should either the plus or minus side of the 12 volt battery that is needed to power the timing light be connected to the engine housing? Thanks.

Richard