Thanks Dave, I found it once I removed the gear change mechanism, it was tucked underneath where there’s a double thickness of steel. I was expecting to find it on the body of the gearbox but it’s on the end cover.
I think the first versions of the gear change were the steel version and the alloy end cover came in a bit later, my bike has no fittings for a hand change so must of come like that.
Richard, I’ve done all of that, the ignition fires both plugs together so you can’t mix up the leads.
And for the first time in my life I even resorted to easy-start, the best I managed was one loud bang !