Electrical Troubleshooting Help Needed

[Spartanman]

1981 XS1100 - Last month charged the battery on 1.5 amp charge after winter hibernation. When I went to disconnect the charger it was pegged all the way into the red and the bike was electrically dead - no lights etc... All the fuses were good. About an hour later I turned the key again and this time everything lit up. After I changed the oil it started up just fine although I didn't take it out on the road. A few weeks later it finally warmed up enough for a ride and after a about 10 miles at highway speed - I lost power, no lights...electrically dead. Trailered it back home and after an hour....lights are back and it starts just fine. Measured 12.6 volts across the battery. However the battery was old and kind of puny looking so I replaced it with the recommended size battery. Started up fine today...went for a ride and after 10 miles at highway speed, electrically dead again. This time I was close enough to push it the last 1 mile....quite a good cardio workout if you are so inclined. Measured 13 volts across the battery.

So it would appear something is getting hot and quitting on me and then recovers once it cools down. Ignition coil? CDI? Something else? Not sure where to start or best way to diagnose...any suggestions would be appreciated. Thanks

[skids]

Clean the key switch contacts, fuse contacts, and maybe solenoid and starter contacts. The kill switch is probably fine. Be careful to make sure it is in neutral gear when dealing with starter and solenoid stuff or it could jump off of the sidestand.

[skids]

Started up fine today...went for a ride and after 10 miles at highway speed, electrically dead again. This time I was close enough to push it the last 1 mile....quite a good cardio workout if you are so inclined. Measured 13 volts across the battery.

So it would appear something is getting hot and quitting on me and then recovers once it cools down. Ignition coil? CDI? Something else? Not sure where to start or best way to diagnose...any suggestions would be appreciated. Thanks

PS, I assume that it is not cranking when you say “electrically dead.”

[DiverRay]

Also, take a look at the "main fuse", under the seat/left side cover. The wires or connection could be bad, and it will cause the symptoms you describe. We had to replace a main fuse at the Durango Rally back in 2011 for the same reason. It, like the rest of the fuses, are the glass type and NEED to be replaced with the newer blade type fuses.
I would also keep an eye on the kill switch. You can order a new right control from mikesxs.com, and just take the guts out of it when it starts to give you trouble.

[motoman]

+1 pertaining to the STOP/RUN switch. Those internal brass contacts get cruddy over the years. This circuit also COMPLETES the running circuit, whether used or not.