Agree that the fast idle clearance seems arbitrary - In standard trim without the choke air jets, my Z1300 seems happy for the clearance to be anything from 0.3-0.55mm (although I have not tried any larger than 0.55mm). With mod fitted, I tried everything from just about zero in 0.1mm steps to 0.55 but without any significant benefits. I came to the conclusion that to make the choke air mod to work for me, I would probably need to re-profile the fast idle cam - but this was just too radical a step for me.
However, it was pretty clear that the choke air jets were very effective in delivering more fuel - if that is your main problem, it seems like a good solution.
