Suzuki TU250X Service Manual page 94

ENGINE 3-47
TRANSMISSION PARTS LOCATION
A 2 mm (0.08 in) B 1 mm (0.03 in)
GEARSHIFT FORK TO GROOVE CLEARANCE
Using a thickness gauge, check the gearshift fork clearance in
the groove of its gear.
The clearance for each gearshift fork plays an important role in
the smoothness and positiveness of the shifting action.
 Shift fork to groove clearance
Service Limit (No.1, 2, 3): 0.60 mm (0.024 in)
 09900-20803: Thickness gauge
If the clearance checked is noted to exceed the limit specified,
replace the fork or its gear, or both.