I noticed that moving my throttle cable slightly in and out of the thumb control housing makes my quad scream with rev's or slow to a stall. If I fiddle with it I can make it so that the quad will idle at the correct speed.......whats going on?

 

Depends on what model you have,but the main point was to have 1/8" slack at the thumb throttle only for the etc and if carb equipped,final idle was adjusted by the idle screw. If it's an efi model,basically the same thing,a little slack at the thumb lever but the tps setting should take care of the idle.If you can turn the handle bars and idle changes then either you don't have enough slack on the throttle cable or it's binding.