Gerrie
Can you check the next thing?
First, you can remove an ignition plug from a engine head, and set it in a plug cap of CDI.
Then, turn on the power supply of CDI.
Short-circuit 1,3pin of the sensor input connector of CDI.
And, open it.
At that time, can you confirm electric discharge on an ignition plug?
If it was so, a cause was shown in the following.
1) A hall sensor broke down.
2) An electric wire was open between a hall sensor and CDI. [:-]
kobago