Fixing 3:rd gear on ZX9 -98 - undercut?

Problem I had with the bike is 3:rd gear jumping out and it got worse
by time.

I have now split the crankcase and disassembled the two transmission
shafts. I was almost certain to find wear on gears and dogs on the
gears but they look ok. At least what I can see. I have never worked
on a bike transmission before but with Haynes manual it was easy to
take it apart.

Can someone tell me what I'm looking for here? Dogs and gear-tooths
looks fine. 3:rd/4:th gear look darker than the other, almost like it
got hot or something. Maybe it should look like this. The dogs "hook"
in to the other gears like they should but they tend to go apart if
you put some force to them (they don't lock themselfs together
harder). Do I need to replace 3:rd gear pairs even if they look ok?
Could the problem be in the gear change drum or the three forks?

Hope someone can help me out here

Best Regards,
Henrik Olofsson
Sweden

 

Usually the forks bend - It does't need much to band one - missed gear etc.

If there is there any markings ( scoring ) on any of the selector forks -
they need to be replaced.
Same with the gears on both shafts

Tis a common zx9 problem