where abouts is it running rich?
idle, progression, quarter throttle to three quarter or flat out?
you will need to alter a different circuit for each of the above, careful though as there is a MASSIVE effect on needle and jet changes on the GSXR11 at about three quarter throttle.

has someone fitted a dynojet kit then returned it to standard airbox? changed exhausts recently?, what condition is the air filter? have you adjusted the valves recently? plugs cleaned and gapped/replaced?

lots of questions.........neeeeeeeeeed more info.

idle mixture screw is under the carb, close to the inlet manifold, infront of the float bowl...