Motorcycle Repair: 1984 Yamaha 400 Special II Ignition problem, secondary windings, plug caps

Question
Mark, This 1984 Yamaha 400 Special II's left cylinder is not getting fire. New plugs. I swapped the "coils" (under gas tank) around and the left side still doesnt fire, but right side does. So I figure something in the ignition is corrupt before it gets to what i think is the coil (comparing to auto coils). Where can I find a diagram or learn the basics so I can troubleshoot it or fix it?

Answer
Hi Marty,

The problem could be a variety of causes. Check for clean, tight connections with multi-connectors and bullet connectors. Check pick up coils for continuity and spec resistance as in service manual. Check primary and secondary windings of ignition coils. Check secondary leads, plug caps, and plugs. Check voltage to suspect coil.

I've seen only 3 defective or bad ignition coils in 25 years.

If I had your email address as requested, I would have attached test and repair files.

Respectfully,
Mark Shively