The looped back wire usually works ok, but sometimes the wire flexes and you can't get the throttle to close all way, or it's not very smooth. It's easy to make a bellcrank system using and extra servo arm. Simply screw and arm (or wheel) to the front of the motor mount, on the side with the throttle. You can tap and thread or use a small sheet metal screw. Don't tighten so far that the servo arm doesn'e move. Epoxy on the screw will keep it in. Run the throttle rod to a hole in the bottom of the arm and another from the top of the arm to the carb throttle arm then check the direction of travel and adjust accordingly.