Thanks to all, after rebuilding the engine again, checking pistons, rings etc, speaking to local electronics expert Geoff at the Scott club meeting, Boyer at length both without doubt say wasted spark does not cause a problem. I then found that I had a poor connection at the coil also the engine earth was a bit ropey, after fixing these I swapped the leads round on the coil, the odd spark jumping across the gap between the plug and rad has now stopped, pickup is better but as I have not got a main jet as yet (got sent mono bloc type) the engine is a bit weak as it rev’s, higher up the range. The carb has no noticeable wear, but I have replaced the float and feed needle, needle jet which have all made an improvement. Just the main jet to go.
The last short run I did the bike pulled reasonably well in top gear at 30mph up to about 50-55mph didn’t want to try anymore as weak mixture and running in. Also added small extension to the carb and added a bell mouth with gauze. Sad to say i’m still going to pass on this bike as I will probably do the same with my Silk when its finished, just making a crankshaft for it. Thanks to all Kev