Yamaha YZ250F(E), Owner'S Service Manual

Page: 264 / 356

TRANSMISSION
5-71
CHECKING THE SHIFT DRUM ASSEMBLY
1. Check:
• Shift drum groove
Damage/scratches/wear

Replace the
shift drum assembly.
• Shift drum segment “1”
Damage/wear

Replace the shift drum as-
sembly.
EAS1SM1293
CHECKING THE TRANSMISSION
1. Measure:
• Main axle runout
(with a centering device and dial gauge “1”)
Out of specification

Replace the main ax-
le.
2. Measure:
• Drive axle runout
(with a centering device and dial gauge “1”)
Out of specification

Replace the drive ax-
le.
3. Check:
• Transmission gears
Blue discoloration/pitting/wear

Replace
the defective gear (s).
• Transmission gear dogs
Cracks/damage/rounded edges

Replace
the defective gear (s).
4. Check:
• Transmission gear movement
Rough movement

Replace the defective
gear (s).
EAS1SM1294 INSTALLING THE TRANSMISSION
1. Install:
• 5th pinion gear (24T) “1”
• 3rd pinion gear (18T) “2”
• Collar “3”
• 4th pinion gear (18T) “4”
• 2nd pinion gear (16T) “5”
(to the main axle “6”)
TIP
Before installation, apply molybdenum disulfide
oil to the inner and end surface of the idler gear
and to the inner surface of the sliding gear, then
install.
Main axle runout limit
0.08 mm (0.0032 in)
Drive axle runout limit
0.08 mm (0.0032 in)
3
4
2
1
6
5
M