It's about electricity. And the beginning of the story was that there were electricity problems on a very nicely restored classic.
Fortunately they were mechanical in nature and I had already paid my tuition fees in the past. Sometimes your experience can make you look good. Because what was the case? The beautiful, deep glossy powder coat provided an insulation layer between the various places where wiring on the frame had to create 'mass'.
white is better
With the almost real Dremel, some scrapes were made in the powder coating down to the bare metal. After that everything worked fine again. With weathered (Italian) engines that have not been restored, this kind of malfunction also sometimes occurs. But then they come from ordinary corrosion, dirty or almost burnt connections. In such cases, simply pulling extra ground connections may not be the solution that deserves the beauty prize, but it can be problem-solving. The main mass bypasses can then come from the headlight to the frame and from the negative of the battery to the frame.
Those poles again!
If the battery voltage across the terminals is good, but the starter motor does not get past the disconsolate ticking of the starter solenoid, it could be a wiring design inherent in the wiring. Or it could be another case of dirty contacts/ground. Perhaps the start button has become rickety due to years of moisture. Both these phenomena are linked to the age of the engine in question.
Where mass problems can be solved with bypasses, there is also a '1.0 solution' for these kinds of starting problems. The starter motor relay is intended to be energized briefly to crank the starter motor. If the starter motor itself does work (just connect the battery directly to the relay), then the problem can be solved simply, effectively and without annoying knowledge of electricity. You pull a wire (for sale per meter at the better car parts store) from the plus of the battery to a normally open pressure switch. From there you go to the starter motor relay terminal (scrabble!), and you have direct energization with no losses or transition resistance to that relay.
Cheap is expensive
It is better not to use AMP plugs from the almost free collection boxes. These things are often made of material that is only slightly thicker than aluminum foil. With the AMP pliers you usually don't press them together firmly enough to get a firm connection between the wire and the AMP plug. That is asking for trouble. But if you use the right stuff. Then it is: Push and walk. And that for an indefinite period of time. You can get the good stuff at the auto parts store. They are also cheaper there than at the Praxis or Gamma.
Better right than left
Place that new starter switch on the right handlebar, as close to the handle as possible. Because when you control that switch and the throttle on one side, you keep your other hand free to choke. It is recommended to lay the new wire in such a way that there are no problems compared to the steering angle. And you score bonus points if you neatly tape the new wiring where necessary.
The loose plug comes off the ignition and is now just useless.