First, set your End Points to 100% both ways. The TX trim should be centered. Fit your servo arm and carburetor linkage at full throttle. The servo arm should be about 45 degrees off center on the servo. Now, lower the throttle stick and watch the carb barrel. When it gets to the "idle" position, adjust the ATV so it limits the movement to that. The trim travel should be enough to raise the idle if needed and cut the engine off when lowered. Since the ATV usually goes 120%, you can fine tune the top end if necessary.

Dr.1