Electrical problems

[Dan soar]

I recently have had my 1980 750k running. It was running very rough and would not return to idle properly. It would sit after Erving the engine on around 3000 rpm, then when you would adjust the idle screw it would drop down to nothing and stall. I replaced the battery with an antigravity battery. The charging system was working. The battery has 13.34volts (not running). Yesterday I was trying to get the bike to idle properly when it died, then when I went to restart the bike the electrics cut out. No lights on the dash at all, no nothing on the starter button. I checked all the fuses nothing blown. I checked the main fuse at the starter solenoid, also not blown. I checked the volts across the starter solenoid,13.34 volts from the battery to the terminal on the starter solenoid, on the other terminal to the starter motor nothing. I tried to bridge out the starter solenoid to fire up the starter motor, nothing at all. I have pulled apart every connection and cleaned off any corrosion, still nothing past the first terminal on the starter solenoid. Can somebody please help. Is the starter solenoid fried?

[TOOLS1]

If the solenoid is fried, you should be able to jump across the posts on it and crank the engine. I would suggest the main fuse at the solenoid, but you already checked it, so I would check the ground strap.
TOOLS

[Dan soar]

I checked the main earth from the battery to the frame, that's all good. The only other grounding is at the coils, I have cleaned up at the frame and reattached the earth. Is there another earth wire?
I am going to pull the starter motor out and test it, does it have an earth strap?
I am really puzzled about this, it might have to go to the shop for a fix, my wife says I'm giving up to easily.

[TOOLS1]

The starter grounds directly to the case, and the coils are not really grounded at all. The metal to metal contact is for heat. It acts as a heat sink to cool the coils. If as you described, you are not getting any power anywhere, you can rule out the ignition system as the problem, as it only fires the sparkplugs, and has nothing to do with power, or charging. I would bet it is either the metal fuse strip by the solenoid, the hot wire to the ignition switch, or the ignition switch itself. Electricity is like a river. It flows, and any break in the system is like a dam. Take a test light and find the dam. Just because a fuse or connection look good, does not mean they are good.
TOOLS

[Dan soar]

After sinking some cold tininies, and half stripping the wiring harness. All roads were leading back to the main earth. Off it came, filed the frame and all components. Smeared some light grease on everything and reassembled. To my amazement I got full power back. Yay.
Thanks Tools, you are a nice bloke. I hope I can help you out one day.