Yamaha Wr250r 2008 Manual

 
TRANSMISSION 
5-67 
EAS26260 
CHECKING THE SHIFT FORKS 
The following procedure applies to all of the shift
forks.
1. Check: 
 
Shift fork pawl “2”
Bends/damage/scoring/wear  
→ 
 Replace the
shift fork. 
 
Shift fork cam follower “1”
2. Check: 
 
Shift fork guide bar
Roll the shift fork guide bar on a flat surface.
Bends  
→ 
 Replace.
WARNING
 
EWA12840  
Do not attempt to straighten a bent shift fork 
guide bar. 
3. Check: 
 
Shift fork movement
(along the shift fork guide bar)
Rough movement...

 
TRANSMISSION 
5-68 
2. Measure: 
 
Drive axle runout
(with a centering device and dial gauge “1”)
Out of specification  
→ 
 Replace the drive axle.
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 engagement
(each pinion gear to its respective wheel
gear)
Incorrect  
→ 
 Reassemble the transmission
axle assemblies.
NOTE:...

 
TRANSMISSION 
5-69 
EAS26340 
INSTALLING THE TRANSMISSION 
1. Install: 
 
Transmission
2. Check: 
 
Transmission
Rough movement  
→ 
 Repair.
NOTE:
 
Oil each gear, shaft, and bearing thoroughly. 

 
TRANSMISSION 
5-70 

 
1
2
3
4
5
6
7
8
9
 
COOLING SYSTEM 
RADIATOR .....................................................................................................6-1  
CHECKING THE RADIATOR...................................................................6-2
INSTALLING THE RADIATOR.................................................................6-2  
THERMOSTAT ...............................................................................................6-4  
CHECKING THE THERMOSTAT...

 
RADIATOR 
6-1 
EAS26380 
RADIATOR 
Removing the radiator
Order Job/Parts to remove Q’ty Remarks 
Seat/Air scoop (left/right) Refer to“GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to“FUEL TANK” on page 7-1.
CoolantDrain.
Refer to“CHANGING THE COOLANT” on 
page 3-18.
1 Radiator fan motor coupler 1 Disconnect.
2 Radiator inlet hose 1 Disconnect.
3 Coolant reservoir hose 1 Disconnect.
4 Radiator outlet hose 1 Disconnect.
5 FID Hose (radiator side) 1
6 Radiator cover 1
7 Breather hose 1 Disconnect.
8...

 
RADIATOR 
6-2 
EAS26390 
CHECKING THE RADIATOR 
1. Check: 
 
Radiator fins “1”
Obstruction  
→ 
 Clean.
Apply compressed air to the rear of the radi-
ator.
Damage  
→ 
 Repair or replace.
NOTE:
 
Straighten any flattened fins with a thin, 
flat-head screwdriver.
2. Check: 
 
Radiator hoses (IN/OUT) 
 
Radiator pipes
Cracks/damage  
→ 
 Replace.
3. Measure: 
 
Radiator cap opening pressure
Below the specified pressure  
→ 
 Replace the
radiator cap.

 
a. Install the...

 
RADIATOR 
6-3 
b. Apply the 100 kPa (14.22 psi) (1.0 kg/cm 
2
 
)
pressure.
c. Measure the indicated pressure with the
gauge.

 
3. Measure: 
 
Radiator cap opening pressure
Below the specified pressure  
→ 
 Replace the
radiator cap.
Refer to “CHECKING THE RADIATOR” on
page 6-2.
1 

 
THERMOSTAT 
6-4 
EAS26440 
THERMOSTAT 
Removing the thermostat
Order Job/Parts to remove Q’ty Remarks  
Seat/Air panel (left/right) Refer to“GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to“FUEL TANK” on page 7-1.
Drains the coolant.Refer to“CHANGING THE COOLANT” on 
page 3-18.
1 Radiator inlet hose 1 Disconnect.
2 FID hose (thermostat side) 1 Disconnect.
3 Thermostat cover 1
4 Thermostat 1
For installation, reverse the removal proce-
dure.
1
2 3 4
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) 
T R..2 Nm (0.2 m...

 
THERMOSTAT 
6-5 
EAS26450 
CHECKING THE THERMOSTAT 
1. Check: 
 
Thermostat “1”
Does not open at 70.5 
– 
73.5 
°  
C
(158.9 
– 
164.3 
° 
F)  
→ 
 Replace.

 
a. Suspend the thermostat “1” in a container “2”
filled with water.
b. Slowly heat the water.
c. Place a thermometer “3” in the water “4”.
d. While stirring the water, observe the thermo-
stat and thermometer’s indicated tempera-
ture.
NOTE:
 
If the accuracy of the thermostat is in doubt, re-
place it. A faulty...