Wiring, Ignition coils or maybe a bad stator assembly
You can test the exciter and pulser coils on the stator assembly for resistance
Exciter should be 129 ohms +/- 20%
Pulser should be 23 ohms +/- 20%
You can also test the Ignition coils
Primary winding (should be blue and brown wires) 0.37 ohms +/- 20%
Secondary winding (Spark plug wires) 10.2K ohms +/- 20%
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Good luck man and let us know what you find!