Motorcycle Repair: 1980 Yamaha XJ650 No Spark on Cyl. 1 & 2, yamaha xj650, plug caps

Question
Replaced the battery and spark plugs but no spark on the left side (cyl 1 & 2 ). To make sure the new plugs were OK, I switched the plugs from the cyl. 1 & 2 and installed them in the the 3 & 4 cyl. Nothing wrong with the plugs but still no spark on the 1 & 2. If one of the coils were bad would it not effect cyls. 1 & 3 or 2 & 4? What should I check next? If I can get it running I'll take it into the shop and have it checked out.


Answer
Larry,

Try swapping coils and see if the problem migrates to the other cylinders.

I suspect the secondary leads or plug caps are defective on the non-firing cylinders.

Cylinders 1-4 & 2-3 fire together. Firing order is 1-2-4-3.

Why don't you include your email address as requested and explained in my instructions?

Respectfully,
Mark Shively