So, update after inspection:
xschris: chain slack is correct, its around 20mm. With the bike on center stand, there is no significant difference between wheel resistance in neutral, or in gear with clutch in. So we can eliminate clutch drag i suppose.
I inspected and reinstalled this today:
- clutch: basket and all components look good and teets withou damage. Friction plates and springs measurements were done, everything is like brand new. Main bearing behing clutch looks good, no resistance when turning, no strange sounds. I think clutch is not the issue
- primary drive gear: teets looks good, no damage, When I was reassembling primary drive gear and clutch basket with gear, in manual there is written that each primary drive gears has letters A - F marked on them, and when replacing, the letters should match. If not there can be increased gear noise and wear. Interesting, but i dont think that was my issue, or?
I did not find any letters on small or big(clutch basket) gear. Strange to me, but i put it back in.
- kickstarter: was working before, after inspection, nothing broken or worn, so i reassembled, and tested, it works again. There is nothing dragging when i was turning the engine, so it looks that kickstater is disengaging as it should, and it will not be my issue.
- oil pump: both gears undamaged, working as they should, pump itself is withing the limits, clean and working. I think not the issue.
I did not ride it after this part, because i dont have new right side cover gasket, so I have to wait until delivered, but overall I dont believe that there was something wrong with those parts.
I will remove electric starter chain, to disconnect starter from starter clutch, because maybe starter clutch dragging and starter motor is making this noise?
The worst scenario will be transmission as the main issue. To inspect tranny, i have to split cases, correct?
What are your thoughts?