Long time ago I started this topic - and in between I've been working on my ship a couple of periods, so its time to continue/round of....
After trying out all the good ideas and tips from you all, my mechanics got the problems pretty well located, mixed problems with mag and amal...
As I said earlier I just had a reconditioned mag put on, but there still seemed to be a problem with sparks, so he swapped mag - and it also turned out that the carb had developed a hair thin crack along the casting seam on the side, along with excessive wear in the slide, allowing lots of false air, so a new concentric went on as well. We also ended up with a bigger main jet.
So at the moment my A10 is a 1 kicker (mostly)
and she's got a lot more pull as well. Regarding the start and idle on 1 cyl. there is still a bit at cold start, but after a short while fast idling everything settles down to a steady idle - but strange enough it seems to miss a heartbeat once in a while, when idling - is that something any of you are familiar with.
But at the moment I am very optimistic and looking foreward to the BSA summercamp in Kent this month.
regard
Joergen