I think the return spring is already there.. it is under the arm you are hooking to.. The picture Bungle drew up is spot on.. that is how the throttle is supposed to attach... just typically it's on a snowblower, so the cable mounts on the bottom.. as most any (stationary engine) the throttle cable PUSHES the throttle open... SO on a minibike or Kart, where you PULL the cable, it goes as shown.. :mellow: