Motorcycle Repair: CDI unit failure, honda cm400t, mcm electronics

Question
I have a Honda CM400T 1981, a few months ago it lost all power and refused to rev out. I traced the problem to the CDI unit which was not advancing the timing hense it would not rev cleanly and lacked acceleration. The fauty unit was replaced and all was fine but the same thing has just happened again so something must be causing the unit to fail in this way. I am a motorcycle mechanic but have never come across this problem before or and no one I know in the trade has either (normally a cdi unity fails completely). Could you sujest where to start looking for the problem that is causing the unit to fail in this way so another expensive cdi unit will not be waisted?
Regards
Rick


Answer
Hi Rick,

Only things that come to mind are poor grounds and voltage spikes. That's a rare problem for Honda models. This problem is very difficult to isolate/diagnose.

Know any electronic techs? Do you have any electronic tech schools where yu are? If so, think about having them check the system. Trouble I have is obtaining specs on the electronics inside the components. Manufactuers don't label their semi-conductors preventing cross referencing electronic parts. (My GSX-R altenator failed. The faulty chip was $12 at MCM Electronics. The altenator was $640 to replace. I was lucky to have found the chip in a catalog.)

What school did you attend? AMI, MMI, etc...

Send me an email. I'd like to share my MC files with you.

Respectfully,
Mark Shively