Now you're walking that tech Grn, I had thought of that or using a bore scope through the oil filler neck to take a look around in there. The problem is the lever has to come out or at least disengage and rotate 90 degrees anticlockwise to remove the clutch cover. The lever is bound up and won't release until you pull in the lever and relieve that bind. It seems no way to win, you're chasing something that can't be seen.
Forget the clutch plate sticking theory, bad idea, doesn't fit what's going on. I do know this, of the four guys that have the same issue, one fixed it by tightening up his clutch freeplay, pop gone! The other guy said his quit popping on it's own, something wore in or smoothed out a rough edge?
There are now only two of us left and the other guy is no help, basically waiting for me to solve this puzzle.
Grn, I'm at a loss here, I've absolutely run out of theories now.
Could that lever be getting so hot that it is jamming something up due to expansion?
IDK, I need to dream up a further test of some sort. One clue, zip-tyeing the clutch lever back as it cools stops the pop. Don't know if that is significant or not.