"Howdy Gary,
This motor uses
"Howdy Gary,
This motor uses a cable from the twist grip tiller to the carburetor. Yes there is a pretty positive throttle return spring at the carb. I've never seen these springs break but anything is possible. More likely you have something binding the cable or the the throttle "brake" mechanism in the tiller is hanging up due to possible overtightening. First take off the hatch cover and look at the spring on the carb to make sure the screw that holds in in place is there and that it is connected to the throttle plate shaft and accelerator pump lever. This should be an easy fix when you find the reason for the fault.
Good luck."