Antique Engines & Machinery
WICO Magneto Tester

WICO EK magnetos are relatively common and often in need of a bit of repair before they can be used again. Rather than testing newly rebuilt magnetos by swapping them with those on finished engines, it is easier to build a tester that can be used on the workbench.


The primary concern when testing an EK is that the armature must be pulled from the core quickly, in a snapping action. If the armature is pulled away slowly, the magneto will not spark. This is accomplished with the use of a long lever to pull the armature away from the core. The armature cannot be pulled from the core by hand when the magnets are properly charged.

Another concern in testing any magneto is that the high tension lead is either grounded or connected to a sparkplug. NEVER run ANY high tension magneto unless the sparkplug terminals are grounded or connected to sparkplugs.

If the high voltage circuit is incomplete, the buildup of electricity, which can be 20-30 thousand volts, will have no place to go. This buildup of high voltage will seek the easiest path to complete the circuit, which can be through the insulation of the coils. This "shorting" will cause degradation of the insulation and possible failure.

This tester was built for simplicity. The 1/2" wrench that is used as a lever to trip the magneto is also used to tighten the 5/16" bolts that secure the magneto.


The armature on an EK can be completely removed from the core of the magneto just by pulling it downward. On an engine this is prevented due to the configuration of the trip mechanism. On this tester, the 1/2" bolts that serve as fulcra for the lever are placed so that the travel of the armature is limited.

The sparkplug has a 1/2" pipe thread. The mount for the plug is a piece of pipe coupling that is welded to the tester.

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