Am I missing a screw here?
On all the ones I've had, the throttle cutoff either has a threaded screw to hold a ringlet like you have there, or a spade connection. That one looks like something is broken off. If you have an ohm meter, slip a piece of plastic or cardboard between the wire and the throttle and see if you have a circuit from that circular spot and the wire. If so then you might check into drilling and threading a hole to hold the ringlet. Just a thought.