Hi, it may just be some shifter linkage
that is damaged or out of place.
Check all your outer shift linkage first
to see if something is jammed. If it looks
okay then you will have to drain the oil
and remove the right engine cover where the
Before removing the clutch unit itself have a
look near the rear of it at the shifter
parts that attach to the shifter shaft
going through the engine to the shift pedal lever.
Try working the shift lever and see if you can see
anything broken or out of place.
There will be a return spring and a plate
that rotates the shift drum when you shift.
The shift drum turns and moves the shift forks
inside the transmission. The forks move the gears
You can only access the shifter parts on the outside
not the drum or forks or gears themselves
which are inside the engine.
Check the shifter mechanism and look for any bent or
broken springs or other related parts in there.
The clutch will have to be removed to change anything
in the shifter area.
Let me know if you need more info.