90’ heritage classic evo 1340 5 speed 45k miles.i have an intermittent knocking noise by clutch area in primary or transmission. Whatever the knocking is coincides with wheel speed. Primary chain is tight fluid is good. After I put it in jack the noise stopped but it definitely has a significant knocking noise when it happens.

 

seems to happen under load
shifts okay
clutch lever feels fine
doesn't grind/whine or squeal