The choke goes gar gars because when the blades are engaged the throttle opens up and more air is sucked past the butterfly which tends to close the choke , which stretches the spring which then pulls the choke back and the air pushes it closed , the spring stretches and thus they cycle continues.
Cut 2 turns off th short ens of the spring then bend the next one out 90 deg to fit over the pin
I’ve worked on dozens of these units and don’t understand what is going on. I’m going to have to get to the shop to see what a new unit looks like. Something tells me you don’t have something hooked up correctly. Will get back to you as soon as possible.