easy way to set throttle linkage vorrectly is unscrew the servo horn, that thing that connects to the throttle servo, its most likely black and plastic, then on your radio set your throttle to neutral, make sure the trim is in neutral too. then put the servo horn back on but making sure the carb is closed as far in as possible, you ownt close it all the way because of the idle screw, but just push on the linkage and set the servo horn on the servo making sure the throttle is closed