Yamaha YZ250N Owner's Service Manual page 354

TRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H3000
REMOVAL POINTS
EC4H3230
Transmission
1. Remove:
9Main axle 1
9Drive axle 2
9Shift cam
9Shift fork 3
9Shift fork 2
9Shift fork 1
NOTE:
9Remove assembly carefully. Note the position
of each part. Pay particular attention to the
location and direction of shift forks.
9Remove the main axle, drive axle, shift cam
and shift fork all together by tapping lightly on
the transmission drive axle with a soft hammer.
EC4H4000
INSPECTION
EC4H4200
Gears
1. Inspect:
9Matching dog a
9Gear teeth b
9Shift fork groove c
Wear/Damage
2. Check:
9Gears movement
Unsmooth movement
EC4H4600
Bearing
1. Inspect:
9Bearing 1
Rotate inner race with a finger.
Rough spot/Seizure
4-72
ENG
Replace.
Repair or replace.
Replace.