The cutout relay is supposed to spring open from its own spring tension, plus a reversal of the polarity of the magnet when the engine stops and current tries to flow backwards through the generator windings. If the points are a little sticky, the connection stays made long enough for the cutout relay to re-energize in the reverse direction, and hold the points closed while discharging. That's why I don't reccomend cleaning or filing the relay points. It's almost impossible to get them smooth enough to separate cleanly when the current tries to reverse.
One very important adjustment is "closing voltage". The cutout relay should not try to close until the armature voltage reaches at least 7 volts. This can be checked by slowing the idle down until the armature voltage is 6 volts or so, and carefully increasing speed until the points close. This assures the generator voltage is high enough to charge the battery, not allow it to discharge through the generator. When charging against a fully-charged battery, the voltage regulator (far right of the three coils) should be adjusted to 7.5 volts. If you don't have a very accutate volts-ampere tester, get an experienced charging system shop to make the adjustments.
Jerry
