Originally Posted by DR. V-TWIN

Also check that the ground to the motor is tight.

Drew

Originally Posted by SauerKraut

This just happened to me last week. If you have a multi meter perform the folling checks. Check battery volt to insure it has at least 12-12.2 volts. Check stator for continuity with the ignition off it should be 0 ohms.Then with engine running unplug stator plug at voltage regulator. Idle up engine to 2000 rpm AC voltage should be at aorund 45-60 volts AC (20-28 volts per 1000 rpm) much more or less than that, probably a bad stator. If stator checks out and battery holds a charge overnight when removed from the bike, either you have a loose ground or a bad votage regulator. For me it was a bad stator, but I replaced the regulator and battery too becasue my was overcharging, which can fry a regultor and battery.