All of the above, most likely an air leak, wrong slide is unlikely but one never knows, if its a slide its more likely a torn or perforated seal on the top of the slide ( i belive those are cv carbs??)
I have never been able to solve that problem on any bike without a through going over and carb rebuild. Lots of places for air to get into the carb. Look at the parts fiche for the intake system and the carb... multiply points for bad seals and air leakage.
Check sticky throttle and air leaks first.
Good luck!
I believe its called "Oppositional Defiance Disorder"
