You need to wind in the idle screw then turn it out about 1-1 1/2 turns, as mentioned above check your choke. Make sure it locks in all positions, when I got mine it wouldn't pull all the way out let alone lock in any position.
Check the small black tube that attaches from one carb to the other. And make sure your carbs are in sync.
Mine would take ages to start all because the previous owner never done any of this, didn't help that he never fitted the screw kit that came with the tors eliminator!
Good luck, it's good to see another uk banshee