No spark from Ignition Coil feeding plugs 1 and 4 - 1992 Yamaha seca II XJ 600

[HazMatt]

My 1992 Yamaha XJ600 (Seca II) was not firing on all cylinders - when I would start her up, the left muffler was cold, and it was obviously much weaker.

Spark plugs 1 and 4 (from coil 1) do not spark. I bought new plugs and still no spark. Should I get a new coil?

 

[VonYinzer]

Probobly. Check the wiring as well. Make sure everything is clean and properly connected. You can also switch the coils around to see if their functioning.