Hi Brian
I dont think its the curtis.More probably the microswitch at the speederpedal.This is a common problem.DONT measure it,change it,and with a good quality,not a cheap one.
It could also be another problem,depending on which cityel you have.Try this.If you press the speeder a bit,and it works,and at the same time you press the brake pedal,and the speeder stops working,and the relay in the back releases,then you have a brake/speeder-relay,and that relay can also give problem.it needs to be shorted.
Alan