Yeah, I think you have a unique problem that probably involves a bad wire or corroded connection.
For instance: you have voltage going to ignition coil but is the coil primary ground side circuit reliably connected? That sort of stuff.
I don't know if that pulsar generator has to have an external ground but, if it does, that would be through the mounting bolts. So, it might be worth your while to make sure the mount holes are clean and the bolt threads aren't rusted.
I'm looking into how that "set plate" is supposed to be adjusted but, if you've got the manual, you could see if you can look that up too.
Also, don't rely on Ohms testing to find a bad wire. Too easy to be misled. Wiring must be load tested to find excessive resistance. I use a sealed beam headlamp and 12v lawn tractor battery for that. That way you can isolate the wire from the system for testing.
Good luck.