Quickie, I had a similar problem and found it was the throttle plate sticking.&nbsp\\; Took off the air cleaner and sprayed some carb cleaner on the plate and cleaned it up.&nbsp\\; Worked for me.
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Had that problem with my 07 RK after the dealer installed new bars and throttle cable, further investigation found there was too much slack and the cable was binding up, adjusted the cable and what do ya know it was fine, check if there is any play with the grip, you should be able to feel the cable pull when you turn the throttle, if it is loose adjust it till the play is gone.