Yamaha Wr250r 2008 Manual

							 
CLUTCH 
5-37 
Removing the push lever shaft
Order Job/Parts to remove Q’ty Remarks  
Drive sprocket cover Refer to “ENGINE REMOVAL” on page 5-1.
Clutch Refer to “CLUTCH” on page 5-34.
1 Clutch cable 1
2 Clutch cable holder 1
3 Push lever shaft 1
4 Push lever spring 1
5 Oil seal 1
6 Bearing 1
For installation, reverse the removal proce-
dure.
1
2 3
4
5
6
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)  
						

							 
CLUTCH 
5-38 
EAS25070 
REMOVING THE CLUTCH 
You need not drain the coolant and engine oil if
you do not service the primary drive gear.
You can reach the clutch housing removal step
by simply removing the cover and clutch cover.
1. Straighten the lock washer tab.
2. Loosen: 
 
Clutch boss nut “1”
NOTE:
 
While holding the clutch boss “3” with the univer- 
sal clutch holder “2”, loosen the clutch boss nut.
3. Straighten the lock washer tab.
4. Remove: 
 
Primary drive gear nut “1” 
 
Lock washer
NOTE:
 
Insert aluminum plate “a” between primary drive
gear “2” and clutch housing “3”, and remove
these parts by loosening the primary drive gear 
nut. 
EAS25100 
CHECKING THE FRICTION PLATES 
The following procedure applies to all of the fric-
tion plates.
1. Check: 
 
Friction plateDamage/wear   
→  
 Replace the friction plates
as a set.
2. Measure: 
 
Friction plate thickness
Out of specification   
→  
 Replace the friction
plates as a set.
NOTE:
 
Measure the friction plate at four places. 
EAS25110 
CHECKING THE CLUTCH PLATES 
The following procedure applies to all of 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 “1”)
Out of specification  
→  
 Replace the clutch
plates as a set. 
Universal clutch holder
90890-04086
YM-91042
1
2
3
12 3
a
 
Friction plate thickness
2.90  
–  
3.10 mm (0.114  
–  
0.122 in)
Limit
2.80 mm (0.110 in)
Warpage limit
0.10 mm (0.0039 in) 
						

							 
CLUTCH 
5-39 
EAS25140 
CHECKING THE CLUTCH SPRINGS 
The following procedure applies to all of 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. 
EAS25150 
CHECKING THE CLUTCH HOUSING 
1. Check: 
 
Clutch housing dogs “a”
Damage/pitting/wear  
→ 
 Deburr the clutch
housing dogs or replace the clutch housing.
NOTE:
 
Pitting on the clutch housing dogs will cause er- 
ratic clutch operation. 
EAS25160 
CHECKING THE CLUTCH BOSS 
1. Check: 
 
Clutch boss splines
Damage/pitting/wear  
→ 
 Replace the clutch
boss.
NOTE:
 
Pitting on the clutch boss splines will cause er- 
ratic clutch operation.
2. Check: 
 
Primary driven gear
Damage/wear  
→  
 Replace the primary drive
and clutch housing as a set.
Excessive noise during operation  
→  
 Replace
the primary drive and clutch housing as a set. 
EAS25170 
CHECKING THE PRESSURE PLATE 
1. Check: 
 
Pressure plate “1”
Cracks/damage  
→  
 Replace. 
EAS25190 
CHECKING THE CLUTCH PUSH RODS 
1. Check: 
 
Push rod “1” 
 
Push rod “2” 
 
Ball “3”
Cracks/damage/wear  
→  
 Replace.
2. Measure: 
 
Push rod bending limit
Out of specification  
→  
 Replace the defective
part (s). 
Clutch spring free length
41.20 mm (1.62 in)
Limit
39.14 mm (1.54 in)
a
 
Push rod bending limit
0.100 mm (0.004 in)
231 
						

							 
CLUTCH 
5-40 
EAS25200 
CHECKING THE PRIMARY DRIVE GEAR 
1. Check: 
 
Primary drive gear
Damage/wear  
→ 
 Replace the primary drive
and primary driven gears as a set.
Excessive noise during operation  
→ 
 Replace
the primary drive and primary driven gears as
a set. 
EAS25210 
CHECKING THE PRIMARY DRIVEN GEAR 
1. Check: 
 
Primary driven gear
Damage/wear  
→ 
 Replace the primary drive
and primary driven gears as a set.
Excessive noise during operation  
→ 
 Replace
the primary drive and primary driven gears as
a set. 
EAS25260 
INSTALLING THE CLUTCH 
1. Install: 
 
Primary drive gear “1” 
 
Clutch housing “2” 
 
Thrust washer 
 
Clutch boss “3” 
 
Lock washer “4” 
 
Lock washer “5” 
 
Clutch boss nut “6” 
 
Primary drive gear nut “7”
NOTE:
 
 
Align the lock washer projection with the clutch
boss slit during assembling. 
 
Install the primary drive gear by facing its flat 
face toward the crankcase.
2. Tighten: 
 
Clutch boss nut “1”
NOTE:
 
While holding the clutch boss “3” with the univer- 
sal clutch holder “2”, tighten the clutch boss nut.3. Bend the lock washer tab along a flat side of
the nut.
4. Tighten: 
 
Primary drive gear nut “1”
NOTE:
 
Insert aluminum plate “a” between primary drive
gear “2” and clutch housing “3”, and tighten the 
primary drive gear nut.
5. Bend the lock washer tab along a flat side of
the nut.
6. Lubricate: 
 
Friction plates 
 
Clutch plates
(with the recommended lubricant) 
 
Push rod 
 
Push rod1 
 
Ball
New
New
71 23
4
6
5
 
Universal clutch holder
90890-04086
YM-91042
Clutch boss nut
75 Nm (7.5 m•kg, 54 ft•lb)
Primary drive gear nut
80 Nm (8.0 m•kg, 58 ft•lb)
Recommended lubricant
Engine oil
TR..
1
2
3
TR..
12 3
a 
						

							 
CLUTCH 
5-41 
7. Install: 
 
Friction plates 
 
Clutch plates
NOTE:
 
First, install a friction plate and then alternate be- 
tween a clutch plate and a friction plate.
8. Install: 
 
Push plate 
 
Push rod 
(onto the clutch pressure plate.)
9. Install: 
 
Push rod 
 
Ball 
 
Pressure plate 
 
Clutch spring
10.Tighten: 
 
Push rod 
 
Clutch spring
NOTE:
 
Tighten the clutch spring bolts in two stages and 
in a crisscross pattern.
11.Check: 
 
Push lever position
Push lever mark “a” and crankcase mark “b”
not aligned  
→ 
 Correct.
NOTE:
 
Move the push lever in the arrow direction, and
make sure that its movement becomes hard in 
the position where the marks match.12.Adjust: 
 
Push lever position

 
a. Loosen locknut “2” of push rod “1”.
b. Return or tighten push rod “1” until the mark
of push lever matches the mark of clutch ca-
ble holder.
c. Hold the push rod (not to move it), and tighten
the push rod locknut.

 
13.Install: 
 
Water pipe “1” 
 
O-ring “2”  
 
Dowel pin “3” 
 
Crankcase cover right gascket “4”  
 
Crankcase cover (right) “5”
NOTE:
 
 
Tighten bolts in a crisscross pattern. 
 
Turn the impeller shaft and check the engaging
of impeller shaft gear and primary drive gear, 
and assemble the right crankcase cover. 
Locknut
8 Nm (0.8 m•kg, 5.8 ft•lb)
Clutch spring bolt
8 Nm (0.8 m•kg, 5.8 ft•lb)
TR..
 
Lock nut
8 Nm (0.8 m•kg, 5.8 ft•lb)
Crankcase cover (right) bolt
10 Nm (1.0 m•kg, 7.2 ft•lb)
ab
TR..
2
1
New
New
TR.. 
						

							 
CLUTCH 
5-42 
14.Install: 
 
Oil cleaner element
Refer to “CHANGING THE ENGINE OIL” on
page 3-11.
15.Install: 
 
Water pump housing cover
Refer to “WATER PUMP” on page 6-6.
16.Fill: 
 
Crankcase
(with the specified amount of the engine oil)
Refer to “CHANGING THE ENGINE OIL” on
page 3-11.
17.Fill: 
 
Cooling system
(with the specified amount of the the coolant)
Refer to “CHANGING THE COOLANT” on
page 3-18.
18.Install: 
 
Brake spring
5
34
12
3
New
New 
						

							 
SHIFT SHAFT 
5-43 
EAS25410 
SHIFT SHAFT 
Removing the shift shaft and stopper lever
Order Job/Parts to remove Q’ty Remarks  
Shift pedal Refer to “ENGINE REMOVAL” on page 5-1.
Clutch housing Refer to “CLUTCH” on page 5-34.
1 Shift shaft 1
2 Plate washer 1
3 Stopper lever spring 1
4 Circlip 1
5 Plate washer 1
6 Stopper lever 1
7 Spacer 1
8 Shift shaft spring 1
9 Stopper screw 1
For installation, reverse the removal proce-
dure.
12
3
4
5
6
7 8
E
E
E
9
LT
T R..22 Nm (2.2 m • kg, 16 ft • Ib)  
						

							 
SHIFT SHAFT 
5-44 
EAS25420 
CHECKING THE SHIFT SHAFT 
1. Check: 
 
Shift shaft 
 
Shift lever
Bends/damage/wear  
→ 
 Replace. 
 
Shift lever spring
Damage/wear  
→ 
 Replace. 
EAS25430 
CHECKING THE STOPPER LEVER 
1. Check: 
 
Stopper lever
Bends/damage  
→ 
 Replace.
Roller turns roughly  
→ 
 Replace the stopper
lever. 
EAS25450 
INSTALLING THE SHIFT SHAFT 
1. Install: 
 
Shift shaft “1” 
 
Shift shaft spring “2” 
 
Stopper lever “3” 
 
Stopper lever spring
NOTE:
 
 
Hook the ends “4” of the stopper lever spring
onto the stopper lever and the crankcase boss. 
 
Mesh the stopper lever with the shift drum seg- 
ment assembly.
1
2
3 4 
						

							 
OIL PUMP AND BALANCER GEAR 
5-45 
EAS24911 
OIL PUMP AND BALANCER GEAR  
Removing the oil pump
Order Job/Parts to remove Q’ty Remarks  
Clutch/Primary drive gear Refer to“CLUTCH” on page 5-34.
Shift shaft Refer to“SHIFT SHAFT” on page 5-43.
1 Balancer weight gear nut 1
2 Lock washer 1
3 Balancer weight gear 1
4 Straight key 1
5 Absorber plate 1
6 Balancer drive gear 1
7 Straight key 1
8 Circlip 1
9 Plain washer 2
10 Idle gear 1
11 Gasket 1
12 Oil pump assembly 1
13 Dowel pin 2
For installation, reverse the removal proce-
dure.
123 4
56 7 89
10
111213T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) T R..50 Nm (5.0 m • kg, 36 ft • Ib)  
						

							 
OIL PUMP AND BALANCER GEAR 
5-46 
Disassembling the oil pump 
Order Job/Parts to remove Q’ty Remarks  
1 Pump cover 1
2 Outer rotor 1
3 Inner rotor 1
4 Dowel pin 1
5 Plain washer 1
6 Driven gear 1
7 Circlip 1
8 Relief valve assembly 1
9 Oil pump housing 1
For installation, reverse the removal proce-
dure.
1
2
3
4
5
6
78 9
E
T R..2 Nm (0.2 m • kg, 1.4 ft • Ib)