Here's a quick update.
Bin meaning to do it for weeks - sorry.
Anyway got a good carb needle from Fieldsheer (thanks again). Took out the crap aftermarket needles put originals back in = it ran even worse so tried every setting under the bloody sun including check ignition timing no joy flat spots, surging and just plain grumpy. So back to drawing board contacted Steve Doran at Motocarb and he supplied me with some alternative Mikuni carb needles (5DI20's). Then set carbs up as manual states. Hey presto its now a happy H1 never run as well, virtually no flatspots, surging with the plugs a lovely chocolate brown colour.
Thanks for everyones help.
Regards
Dave

H1F, Triumph Scrambler 1200xe & a Yam SZR660 project.