Yamaha YZ250 2021 Owner's Manual page 108

EAM20111
CLUTCH
EAM30108
REMOVING THE CLUTCH
1. Remove:
• Clutch boss nut "1"
• Lock washer
• Clutch boss "2"
TIP
• While holding the clutch boss with the univer-
sal clutch holder "3", loosen the clutch boss
nut.
• Do not use an impact wrench for removing the
clutch boss nut.
Universal clutch holder
90890-04086
Universal clutch holder
YM-91042
3
G088993
EAM30109
CHECKING THE FRICTION PLATES
1. Check:
• Friction plate
Damage/wear  Replace the friction plates
as a set.
2. Measure:
• Friction plate thickness
Out of specification  Replace the friction
plates as a set.
TIP
Measure it at four points on the friction plate.
Friction plate thickness
2.90–3.10 mm (0.114–0.122 in)
Wear limit
2.80 mm (0.110 in)
EAM30110
CHECKING THE CLUTCH PLATES
1. Check:
• Clutch plate
Damage  Replace the clutch plates as a
set.
2. Measure:
• Clutch plate warpage
(with a surface plate and thickness gauge)
Out of specification  Replace the clutch
plates as a set.
Thickness gauge
Feeler gauge set
Clutch plate thickness
Warpage limit
EAM30111
CHECKING THE CLUTCH SPRINGS
1. Check:
• Clutch spring
Damage  Replace the clutch springs as a
set.
2. Measure:
• Clutch spring free length
1
Out of specification  Replace the clutch
springs as a set.
Clutch spring free length
2
Clutch spring free length limit
EAM30112
CHECKING THE CLUTCH HOUSING
1. Check:
• Clutch housing dogs
Damage/pitting/wear  Deburr the clutch
housing dogs or replace the clutch housing.
TIP
Pitting on the clutch housing dogs will cause er-
ratic clutch operation.
G088994
5-1
CLUTCH
90890-03268
YU-26900-9
1.50–1.70 mm (0.059–0.067 in)
0.20 mm (0.008 in)
44.00 mm (1.73 in) (YZ250X)
50.00 mm (1.97 in) (YZ250)
41.80 mm (1.65 in) (YZ250X)
48.00 mm (1.89 in) (YZ250)