Hey newbie here but I've got a good one for you! My 99 fire blade had developed a intermittent knock behind the front sprocket that only manifest itself when the bike is in neutral off the kickstand in the upright position! It's crazy because if it's out back in the resting position on its kickstand it goes away !! It doesn't knock at all in any other gear or if the clutch is engaged . Sounds like it's binding on metal or almost like a gaulded bearing . Thinking maybe the output shaft bearing but not sure any thoughts or suggestions would be great!! Thanks

 

I would get my mechanic's stethoscope and put the bike on a stand and track it down that way.
I've used that mechanic's stethoscope on my car's engine, computers and laptops to verify a faulty fan, my building's plumbing and heating system. I think I got my $5 worth!

 

As Tony says, getting to pin point it is your issue. As we all know, sounds can be misleading at times.
I would guess its clutch related. You mentioned it makes no noise when your clutch is engaged so maybe it would be worth investigating there. It could be a shattered friction plate and the debris is jammed in there giving you that binding noise. It could be a loose pressure plate, broken spring ?
I know it's on the other side completely but as I said, pinpointing the area can be misleading.
Best of luck mate