Sometimes you find those little rubber boots perish and then the brass pins don't touch I suggest that you either get a new set and if you do have a trial fit of off the engine so that you get the larger boot in the right position for the pin to go through it and the two little holes in the carby, or what I do sometimes is mount a little switch onto a small plate someware (even up on the handle bars) and wire one side to ground and the other to the coil wire. When the switch is in the closed position the engine will stop (coil connected to ground) This way you have total control.
