I've now chnaged the idle needle and it stops the carb fully closing when the brake is applied.

I now have another problem. When i apply throttle and go back to idle there are no problems. However. when i apply brakes as the throttle arms is returning to idle it pulls open the carb so at idle following brake the carb is half open :-( (hope that makes sense!!)

How loose/tight should the throttle arm and end screw be? Should the throttle arm screw onto the carb or should it be loose? Should the throttle arm washer screw onto the carb or should this be loose?

Cheers