smaller diameter handle means less distance to move, yeah? so for the same amout of movement in throttle as before you'll get a bigger opening of the throttle now, yeah....?
btw, how did you adjust out the play in the throttle cable? I fancy doing mine a teeny bit but am nervous of messing with the throttle. I opened it up and didnt see anything obvious to adjust so just closed it up again....or am i looking at the wrong end of the throttle cable?