Thanks everyone, the diagnoses were spot on. The “plop plop” was fine, so I changed the points, now it fires on two. Although I can’t get a nice tickover like some of the bikes I saw at Abbotsholme. It runs “lumpily” with the occasional misfire. What should i check next ? I am using petrol with a lead additive, and it is 95,could this be a problem.?
Thankyou Roger Hulett