Help! Bike wont start

[eman13261]

So my dad and I went for a 2 day ride to Vermont and at 400 miles away from home my bike died.
Here is what happened
-backfired extremely loud then completely shut down. Didn't start but barely fired twice, followed by nothing the next 2 dozen attempts. Would not start with starter fluid in the carbs either. Held the spark plugs against the engine and no spark so obviously electrical. Plugs/wires/cap/fuses are all good and voltage was good on tci when I checked 700 miles ago before the trip. The neutral light and brake light works but the headlight doesn't. I had to get it towed to a shop and ride two-up with my dad home, I have to go back with a trailer sometime soon. Any guesses?

 

[mrtwowheel]

Dual output coil or two single coils?

 

[retiredgentleman]

Does the bike still have those old original glass fuses? If you just did a visual check of the glass fuses, that's not good enough. They can look good but have high resistance, which causes voltage drop. That would kill the ignition.

Also the TCI is getting old these days. The black box internals may be failing.
Another possibility is the small magnet embedded in the alternator rotor has lost a lot of its magnetism. That small magnet is what triggers the TCI. As a test, you can unplug the rec/reg unit and then see if the engine will start and run normally.

 

[eman13261]

Dual output coil or two single coils?

Single tci

 

[eman13261]

Does the bike still have those old original glass fuses? If you just did a visual check of the glass fuses, that's not good enough. They can look good but have high resistance, which causes voltage drop. That would kill the ignition.

Also the TCI is getting old these days. The black box internals may be failing.
Another possibility is the small magnet embedded in the alternator rotor has lost a lot of its magnetism. That small magnet is what triggers the TCI. As a test, you can unplug the rec/reg unit and then see if the engine will start and run normally.

Thanks for the help, almost positive it was a short in the system due to multiple frayed wires right outside of my fuse box (it was also raining when it occurred). So I think I'm the near future I'm going to replace/simplify the wiring harness, install blade fuses and upgrade the charging system