Hi Mark.
Its not the ignitor as purchased one from Larui. Had a scope on the pick ups and all ok and cleaned all connectors cleaned so no high resistance. Changed coils, leads caps and done away with the ballast resister. One day you can go out and fire the beast up and fine. Leave for an hour and go to fire up again and no spark
Tried all info by members on forum to sort out problem to no avail. Never mind I tell myself One day in my life time will find the fault
All the best in your restorations have a few spares if you need any. Side panels, brake items, rear silencer that needs a new 2 inch pipe brazing on to connect to collector box plus other odds and sods.