Update: We have been pulling the bike around trying to get it to fire up with no joy. I again removed the flywheel as on testing it looked like it was firing just after TDC. Maybe someone has tried to rig another flywheel as when stationary the spark occurs much too late. Does anyone recognise the advance system, I locked it with a screw, to full advance, replaced the flywheel, set the dwell and it briefly fired up. Now of course the case has a gut full of fuel and will not continue to run. Will let it sit open overnight and try again tomorrow.