Intermittent spark on 1 & 4?

I have a 78 KZ650 with Accel coils and a dyna ignition... It has been running fine until recently, where it has been cutting in and out on cylinders 1 and 4. Coils read fine at 4.2 ohms each... They are seeing 11.5 volts with the ignition on... Spark plygs are good, even swapped them out with a new pair... New plug wires. All connections are good.. I'm stumped.. What could it be? It works fine sometimes, and then sometimes it will go a while running on two cylinders... If it helps at all, when I flip the kill switch on and off, sometimes that will get 1 and 4 to fire again...

Try switching the wires from 1 & 4, with 2 & 3 & see if the problem moves to 2 & 3 not firing
Pete

I figured it out,,, After testing the charging voltage, and noticing that it was steadily dropping no matter what RPM I was at, I decided to wiggle the wires going to the stator (just behind the clutch cable cover) and sure enough spark returned... I pulled the cover off and saw that one of the wires were shorting out on the engine block.. I replaced the connectors and charged my battery back up... and now I have spark and good voltage,..

Glad you figured it out...& it was an easy fix.....electrical issues can be a pain , I. t. a.ss, to track down
Pete