Was trying to figure out why my #1 cylinder wasn't firing. I had trouble with intermittent firing for some time and eventually it cut out completely the other day.
I checked the compression, the plug, the coil and everything seemed to be ok. Even retired the coil box and soldered the springs to the long screws.
Finally, I cut the ends off all the wiring harness and soldered new ends ... which fixed the problem. So ... when I was testing the cylinder by shorting out the plug I saw a spark ... but evidently it was not a good enough spark. Hmmm