Hey.... i'm curious... is there anything inside the signal generator rotor (i.e. magnets, wire coils, etc)?
pretty sure the rotor is just a hunk of metal and the pick ups are variable reluctance sensors. The metal moving past the coils in the VR sensors creates a voltage spike when a tooth moves by it.
In the older GS's, there are 2 VR sensor and one tooth on the rotor. In this configuration, the VR sensors directly trigger the firing of the coils. In the newer GS, there is only 1 VR sensor and IIRC the rotor has 5 teeth, one tooth being twice as long as the others. This configuration produces a regular voltage spike with one spike being longer then the others as a referance point. This allows the microcontroller (yes there is a computer in your GS) to keep track of where the crank shaft is in its rotation, which then in turn fires the coils.