Motorcycle Repair: Cdi burns out v45 700

Question
Why would my cdi burn out on the back two cylinder s three times

Answer
Shorted wire from Stator to CDI?  Bad Ground, maybe ad a extra ground
from battery to Frame. Bad connectors. Clean and Lubricate conections.
Bad connections cause heat in wires and electronical components.
Faulty Coils or Defective Plug Wires.
These are just things that come to mind.
Electical Short most Likely...