Hi All and thanks for the reply. Pete great pictures and diagram - there is no lead on cap over points. I think previous owner had electronic ignition at one point. Now back to mag but obviously didn’t fit the lead back to the cap.
I’ll get on with it.
Roger thanks for advice - I have manual so will enjoy the read
Paul
The MAGNETO doesn't know about positive earth of the battery etc. The centre bolt on the rotating points assembly needs to be shorted to the frame anywhere to stop sparks happening. The twins have a button on a cast cap. You reach down and press it. Magneto cut out switches are on the handlebars of bikes made over 100 years ago. They all work the same way. Earth the primary coil windings.They are a safety device as well as a convenience. I've used hornbuttons to do the job. You must hold it down till the engine has completely stopped or use a toggle or such switch if you wish. I use the valve
lifter on singles (and some early V twins). Nev