This is some great information, must read if you have a wheeler:

http://www.dansmc.com/cdiignition.htm
http://www.dansmc.com/electricaltesting.htm
http://hometown.aol.co.uk/bikesparks/CDI_1.htm

Explains it all and really helps take out the guessing of what is working and what is not. Make sure to thank the guys that put the info and the site together.

Scott