Sky - Been there done that. Mine did the same exact thing. All I can tell you is what I did. I had one of the boots going from airbox to carb that had a big split in it. I got new boots and new air filter. ALSO - and I cant say for sure but there was a rubber hose that ran down by the throttle linkage, and it MAY I say May have been interfering with the throttle as it returned. I rerouted that hose. I just got mine fired up a few minutes ago and went for a spin. No idle issues. Good luck! JON