Yamaha WR250FM 2021, Owner'S Service Manual

Page: 251 / 404

CLUTCH
5-51
EAM30108
REMOVING THE CLUTCH
1. Straighten the clutch boss nut rib “a”.
2. Remove:
•
Clutch boss nut “1”
• Conical washer “2”
• Clutch boss “3”
TIP
• While holding the clutch boss with the univer-
sal clutch holder “4”, loosen the clutch boss
nut.
•
Do not use an impact wrench for removing the
clutch boss nut.
EAM30109
CHECKING THE FRICTION PLATES
1. Check:
• Friction plate 1, 2
Damage/wear

Replace the friction plates
as a set.
2. Measure:
• Friction plate 1, 2 thickness
Out of specification

Replace the friction
plates as a set.
TIP
Measure it at four points on the friction plate.
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.
EAM30111
CHECKING THE CLUTCH SPRINGS
1. Check:
• Clutch spring
Damage

Replace the clutch springs as a
set.
2. Measure:
• Clutch spring free length
Out of specification

Replace the clutch
springs as a set.
EAM30112
CHECKING THE CLUTCH HOUSING
1. Check:
• Clutch housing dogs “1”
Damage/pitting/wear

Deburr the clutch
housing dogs or replace the clutch housing.
TIP
Pitting on the clutch housing dogs will cause er-
Universal clutch holder
90890-04086
Universal clutch holder
YM-91042
a
2 2
3
4
1 1
2
3
4
Friction plate 1 thickness
2.70–2.90 mm (0.106–0.114 in)
Wear limit
2.60 mm (0.102 in)
Friction plate 2 thickness
2.72–2.88 mm (0.107–0.113 in)
Wear limit
2.62 mm (0.103 in)
Thickness gauge
90890-03268
Feeler gauge set
YU-26900-9
Clutch plate thickness
1.50–1.70 mm (0.059–0.067 in)
Warpage limit
0.10 mm (0.004 in)
Clutch spring free length
44.00 mm (1.73 in)
Clutch spring free length limit
41.80 mm (1.65 in)