Thanks again , I think at the moment I’m trying all sorts in desperation. I need to be logical, its all to easy to start imaging all sorts of faults.
So I’ll make a fault finding flow chart. three main areas for investigation are:
Spark , spark plugs, HT leads, graphite contacts , magneto HT . Low tension , gap , timing , short circuits.
fuel, fuel flow, float level, jets , slides
gas seal: transfer ports, barrel seal, glad seal, compression rings
I think that’s it !! just need to order them now !!! and research how to test each one