It looks like a lot of bases have been covered here. I do wonder about the "Lack Of Spark"?
Meaning,, that the contact end is a good ways up inside the boot, Did you use a screw driver or something like it stuck up inside the plug wire, then try to go to ground to see that spark is present?
I'm not questioning your mechanical skill but sometimes it the simplest things that get overlooked.
2012 KTM 690 R
2012 KTM 990R Adventure
2014 Triumph Explorer XC
"Walking thru life to an unknown destination and trying to enjoy the adventure getting there"