have you unscrewed the high tension lead out of the coil?
might be a good idea to take it out and cut off 3mm off it then screw it back in.
sorry i am just adding things as they come to me.
whilst youve got it taken out. test it for continuity.
you might want to check this post out also as they had a similar prob to yours
https://www.outdoorking-forum.com.au/forum/u...amp;Main=8118&Number=45181#Post45181