Motorcycle Repair: spark plug not firing, kill switch, spark plug

Question
HI I have a question about a honda 1978 CB400A.I can"t get any fire to the spark plug,can you tell me how the CDI get it power to make the + side of the coil hot when you switch it on,and the kill switch in run.THANK YOU VERY MUCH FOR ANY HELP YOU CAN GIVE ME.LARRY

Answer
Hi Larry.
 The CDI is a totally computerized component.  I do not know it's inner workings.  However, it is the least likely component to go bad in the ignition system.

 Have you checked the fuse for the ignition circuit?  How about a check for shorts in the ignition wiring and the wiring to the CDI from power?  Have you tested the coils as per the repair manual specs?  ALL of those things are more likely to happen than the CDI going bad, but if it does, the only thing to do is replace it.

Good luck.
FALCON