External Plug-In Ignition Module - Harley DavidsonFeature two advance curve families that are adjustable to accommodate stock and modified engines. Selectable multi spark mode for quick starting and smooth cruising. Unit has four rotary switches for timing adjustments, single dual ignition mode and rpm limit (100 rpm steps). Coil outputs protected against short circuits. Require coils with a minimum of 3 ohms resistance and low resistance spiral core type plug wires. Use the tachometer wire for the