[alantf]

As you can see from the drawing, the ignition circuit is for STARTING the bike. To try and simplify it for you, once it's running, the alternator circuit takes over, and runs the bike. Again, from the drawing, when you short out the solenoid. you're putting power directly to the starter motor, without the circuit that pulls in the solenoid coil (and closes the solenoid) being used. That's why it's GOT to be a fault in the starter circuit (possibly a safety switch fault) stopping the solenoid coil (which closes the solenoid main contact) pulling in. All the solenoid is, is a coil which, when energised by the starter circuit, closes the heavy duty contact, and puts around 80A to the starter.