Each time that you service the contact breaker points on your magneto, it is
a simple matter of undoing one or two screws to remove the EasyCap for checking.
If your magneto has suffered badly from a leaking oil seal, clean any traces
of oil from the EasyCap. Also if your magneto has suffered badly from the damp,
ensure that the contact surfaces of the EasyCap are clean and bright and that
the EasyCap is dry.
Many multimeters include a capacitance measuring function that can be used to
check that the capacitance of the EasyCap between its two contact surfaces is
still within specification:
135 to 165 µF for the C01,
C02, C03 and C05;
122 to 150 µF for the C04.
The leakage resistance can also be checked. However, faulty capacitors in
general often only exhibit unacceptable leakage when subjected to high voltage,
and the resistance measuring function of most multimeters only tests at a few
volts. The EasyCap can be checked with a megger, and we recommend using a 500 V
setting. If you do not have a megger, you may be able to find a friendly
electrician who can assist. Once the megger has charged the capacitor up, the
reading should be in excess of 1 GΩ (1,000,000,000
Ohms) or off the scale.
In the absence of suitable test equipment, you can
always check an EasyCap by replacing it with a new one and seeing if it makes
any difference. As it says in many of the old service manuals for coil ignition,
"The best check for a condenser is by substitution." Remember, with the EasyCap,
this is a simple, quick and inexpensive option. By contrast, if your magneto
were still fitted with a condenser buried in the armature, substitution would
not be at all straightforward ... and if the old condenser were potted in resin,
its removal would probably also be its destruction.