read skg's problem, that will start to happen to you next

https://www.kawasakiforums.com/m_156399/tm.htm

 

is your cable good ? no pulling or binding when turned a certain way ?

 

the gear teeth themselves are most likely completely fine. but the engagement dogs are part of the gear (on the side) they will start to wear down and become angled. once that happens the hard acceleration and side loading will make them pop out of gear. sometimes it will recatch but as they get worse it will become nearly impossibly to keep it in gear. (they work the same in car race trannies that use dogs instead of synchros)

from what i've read about kawasaki's it can be caused by the shift forks and shift drum wear down and not fully engaging the gear dogs. but once its gone on long enough to progress to the point you describe the gear dogs would at the very least need to machined flat again if not replacing the whole gear.

i just picked up a replacement set of shift forks and shift drum on ebay. i'm going to work on cryo treating the shift drum and add a thin layer of material to the wear surface of the shift forks with a much higher hardness than stock (along the lines of tungsten carbide). that way if I ever have to swap the parts in i'll have a superior set that won't wear out for a long long time.