I have been slowly bringing my Rc back from the dead and when its up to temp it idles at close to 2000rpms. when i tried to turn the idle down with the knob it was to tight and didnt really turn at all. After taking the box off to get to the injection etc. i saw that when i tured the knob it did nothing where it was hooked up. Could that screw/spring thing just be stuck? How would i unstick that without damaging it? Can i manually do it there at the mechanism?