I was thinking the throwout bearing too. Does the lt clutch have a little ball in it at the end of the push rod like a banshee?
I never had either suzukis bottom end or clutch apart so i dont know.  But i do know my banshee did something similar and i found the ball at the end of the push rod was all beat up, kinda oval.  Replaced with new plates and springs, dont know what actually fixed it but it was fixed.