My parts bike came with a spare CDI. The PO said he spent $300 and it didn't run any better with the new one -- it was a carb problem. I noticed the extra wire and decided to use the older CDI with the correct number of wires and after reading this post I am glad I did. I was thinking maybe the yellow wire went to a tach.
It seems like all things TW start with a "2JX", at least on my '87's. If so maybe "2YG" is significant for some other model that is useable with the TW.

It seems like all things TW start with a "2JX", at least on my '87's. If so maybe "2YG" is significant for some other model that is useable with the TW.
