That red/black wire is the issue. It supplies 12V to the CDI from the run/stop switch. Without that 12V the CDI won't do anything.

If you applied 12V directly to the yellow/black wire on the solenoid you can damage a transistor in the CDI - if 12V at that wire drops to 0V (or close) when you press the start button this is an issue. Blue/black should go from 12V to 0V when start button is pressed, but yellow/black should remain at 12V.