I have also found that it helps if you take the servo arm off, and hold it up to the carb throttle arm. Make sure you are using a hole in the servo arm that corresponds to the hole on the carb throttle arm. That way you get a 1:1 movement of servo to throttle, and you should have to adjust endpoints all that much. This makes a much smoother transition. Whenever you use endpoints to adjust throttle travel, you often times get a point where the throttle moves too much at once, or not enough at once because you are messing up the linear relationship you would expect between the radio throttle movement and the actual engine throttle movement.

Hope this made sense.