Right fellas, listen up, I have an A10 which I have now named Christine (after the 1983 film about a possessed car).
I bought the Kwaka W650 which is arriving soon. However, I took the A10 out today to test the timing reset and needle at P4 to get it ready for a possible sale ........ and ................ it went like s**t off a shovel.
Revved out to 60 in third and, up the bypass on an incline, managed 70 with a headwind and a very, very, slight hesitation at 75. Chucked it around various roads - lovely. No lumpiness on revving from tickover - felt smooth as you like.
So, with thanks to everyone, I can confirm that Andrew (Priory) is correct (for me at least) in saying that 11/32 (ca. 8.5mm) btdc is right for my bike. Running with super unleaded, airscrew 1.5 turns out, c/b at .012, plugs at .018 (new), needle at P4. The 290 main jet seems fine with these settings. Plug chop revealed a very light tan with no sooting (tad lean??).
Now I have the conundrum of selling or keeping for that brilliant A10 experience when they run well. Will still jump on the Kwaka for an assured ride, but the A10 gets my vote for a 'will I make it' rorty ride around Yorkshire. I'm sure the A10 is jealous of the new arrival and has started to behave???