First test I would do is turn each pilot jet on each carb in seperately (Engine running @ idle) gently untill it reaches fully in.. Don't force it, because the small tips tend to break in the carb housing if you tighten it with force..
If you hear one cilinder cutting out on idle, you know the pilot adjustment is working for that carb. If it doesn''t you know that one ain't right.. Could be a faulty O-ring, plugged jet or whatever, but it will pinpoint you in the right directon which carb needs to be adressed.
If all are working it doesn't matter how many turns it should be out.. The preset is just a given startup to go from..
If the bike surges on idle, it can be lean.. This resultst on pops and bangs on deceleration. Also there's hesitation at pick up while riding.. A shudder jerky sensation you slighly open the throttle getting out of the corner..
Besides that, and also when you have to go beyond 3 turns out you might consider the slow jet being too small.. If the slow jet is too rich it would seem to have a dip when you open up the throttle throughout the 2-5 krpm range..
refer to service manual and follow "idle drop" proceedure
try indexing each screw to the point where turning it in cuts firing; from that exact point you experiment by turning out 1, 2 or 3 turns to find what works best.
any cylinder's screw that fails to cut out firing most likely has a slow leak through the float needle or a broken screw tip.