2008 YAMAHA WR 250F Owners Manual

5-41
OIL PUMP
REMOVING THE OIL TANKOrder Part name Q'ty Remarks Drain the engine oil. Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
1 Oil hose 2 1
2 Oil hose 1 1
3 Dowel pin 2
4 Oil tank breather hose 1
5 Oil tank 1
6 Oil strainer 1

5-42
OIL PUMP
CHECKING THE OIL PUMP
1. Inspect:• Oil pump drive gear "1"
• Oil pump drive shaft "2"
• Rotor housing "3"
• Oil pump cover "4"Cracks/wear/damage →Replace.
2. Measure: • Tip clearance "a"(between the inner rotor "1" and
outer rotor "2")
• Side clearance "b" (between the outer rotor "2" and
rotor housing "3")
• Housing and rotor clearance "c" (between the rotor housing "3"
and rotors "1" "2")
Out of specification →Replace the
oil pump assembly. 3. Check:
• Unsmooth →Repeat steps #1 and
#2 or replace the defective parts.
INSTALLING THE OIL PUMP
1. Install: • Oil pump drive shaft "1"
• Washer "2"
• Dowel pin "3"
• Inner rotor 1 "4"
• Apply the engine oil on the oil pump drive shaft and inner rotor 1.
• Fit the dowel pin into the groove in
the inner rotor 1.
2. Install:• Outer rotor 1 "1"
Apply the engine oil on the outer rotor
1.
3. Install:• Oil pump cover "1"
• Screw (oil pump cover) "2"
• Dowel pin "3"
• Inner rotor 2 "4"
• Circlip "5"
• Apply the engine oil on the inner ro-tor 2.
• Fit the dowel pin into the groove in
the inner rotor 2.
4. Install:• Outer rotor 2 "1"
• Dowel pin "2"
• Oil pump assembly "3"
• Bolt (oil pump assembly)
[L = 25 mm (0.94 in)] "4"
• Bolt (oil pump assembly) [L = 30 mm (1.18 in)] "5"
Apply the engine oil on the outer rotor
2.
5. Install:
• Oil pump drive gear "1"
• Washer "2"
• Circlip "3"
Apply the engine oil on the oil pump
drive gear inner circumference.
Tip clearance "a": 0.12 mm or less (0.0047
in or less)
: 0.20 mm
(0.008 in)
Side clearance "b": 0.09–0.17 mm (0.0035–
0.0067 in)
: 0.24 mm
(0.009 in)
Housing and rotor clear-
ance "c": 0.03–0.10 mm (0.0012–
0.0039 in)
: 0.17 mm
(0.0067 in)
Screw (oil pump cover):2 Nm (0.2 m•kg, 1.4
ft•lb)
Bolt (oil pump assem-
bly): 10 Nm (1.0 m•kg, 7.2
ft•lb)
Bolt (oil pump assem-
bly): 10 Nm (1.0 m•kg, 7.2
ft•lb)

5-43
KICK SHAFT AND SHIFT SHAFT
KICK SHAFT AND SHIFT SHAFT
REMOVING THE KICK SHAFT AND SHIFT SHAFTOrder Part name Q'ty Remarks Oil pump Refer to "OIL PUMP" section.
1 Kick idle gear 1
2 Kick shaft assembly 1 Refer to removal section.
3 Spring guide 1
4 Torsion spring 1
5 Ratchet wheel 1
6 Kick gear 1
7 Kick shaft 1
8 Washer 1
9 Shift pedal 1
10 Shift shaft 1
11 Collar 1
12 Torsion spring 1
13 Roller 1
14 Shift guide 1 Refer to removal section.
15 Shift lever assembly 1 Refer to removal section.
16 Shift lever 1

5-44
KICK SHAFT AND SHIFT SHAFT
17 Pawl2
18 Pawl pin 2
19 Spring 2
20 Bolt (stopper lever) 1
21 Stopper lever 1
22 Torsion spring 1
23 Segment 1 Refer to removal section.
Order
Part name Q'tyRemarks

5-45
KICK SHAFT AND SHIFT SHAFT
REMOVING THE KICK SHAFT
ASSEMBLY
1. Remove:• Kick shaft assembly "1"
Unhook the torsion spring "2" from
the hole "a" in the crankcase.
REMOVING THE SHIFT GUIDE
AND SHIFT LEVER ASSEMBLY
1. Remove:• Bolt (shift guide)
• Shift guide "1"
• Shift lever assembly "2"
The shift lever assembly is disassem-
bled at the same time as the shift
guide.
REMOVING THE SEGMENT
1. Remove:
• Bolt (segment) "1"
• Segment "2"
Turn the segment counterclockwise
until it stops and loosen the bolt.
If the segment gets an impact, it
may be damaged. Take care not to
give an impact to the segment
when removing the bolt.
CHECKING THE KICK SHAFT AND
RATCHET WHEEL
1. Check:• Ratchet wheel "1" smooth move-
ment
Unsmooth movement →Replace. • Kick shaft "2"
Wear/damage →Replace.
• Spring "3" Broken →Replace.
CHECKING THE KICK GEAR, KICK
IDLE GEAR AND RATCHET
WHEEL
1. Inspect: • Kick gear "1"
• Kick idle gear "2"
• Ratchet wheel "3"
• Gear teeth "a"
• Ratchet teeth "b"Wear/damage →Replace.
CHECKING THE SHIFT SHAFT
1. Inspect: • Shift shaft "1"
Bend/damage →Replace.
• Spring "2" Broken →Replace.
CHECKING THE SHIFT GUIDE AND
SHIFT LEVER ASSEMBLY
1. Inspect: • Shift guide "1"
• Shift lever "2"
• Pawl "3"
• Pawl pin "4"
• Spring "5"Wear/damage →Replace. CHECKING THE STOPPER LEVER
1. Inspect:
• Stopper lever "1"Wear/damage →Replace.
• Torsion spring "2" Broken →Replace.
INSTALLING THE SEGMENT
1. Install: • Segment "1"
• Bolt (segment)
Align the notch "a" on the segment
with the pin "b" on the shift cam.
If the segment gets an impact, it
may be damaged. Take care not to
give an impact to the segment
when tightening the bolt.
INSTALLING THE STOPPER
LEVER
1. Install:• Torsion spring "1"
• Stopper lever "2"
• Bolt (stopper lever) "3"
Align the stopper lever roller with the
slot on segment.
Bolt (segment): 30 Nm (3.0 m•kg, 22
ft•lb)
Bolt (stopper lever): 10 Nm (1.0 m•kg, 7.2
ft•lb)

5-46
KICK SHAFT AND SHIFT SHAFT
INSTALLING THE SHIFT GUIDE
AND SHIFT LEVER ASSEMBLY
1. Install:• Spring "1"
• Pawl pin "2"
•Pawl "3"To shift lever "4".
Apply the engine oil on the spring,
pawl pin and pawl.
2. Install:• Shift lever assembly "1"
To shift guide "2".
3. Install: • Shift lever assembly "1"
• Shift guide "2"
• The shift lever assembly is installed at the same time as the shift guide.
• Apply the engine oil on the bolt
(segment) shaft.
4. Install:• Bolt (shift guide) "1" INSTALLING TH
E SHIFT SHAFT
1. Install: • Roller "1"
• Collar "2"
• Torsion spring "3"
• Shift shaft "4"
Apply the engine oil on the roller and
shift shaft.
2. Install:• Shift pedalRefer to "AC MAGNETO AND
STARTER CLUTCH" section.
INSTALLING THE KICK SHAFT
ASSEMBLY
1. Install: • Kick gear "1"
• Washer "2"
• Circlip "3"
• Ratchet wheel "4"
• Spring "5"
• Washer "6"
• Circlip "7" To kick shaft "8".
• Apply the molybdenum disulfide oil on the inner circumferences of the
kick gear and ratchet wheel.
• Align the punch mark "a" on the ratchet wheel with the punch mark
"b" on the kick shaft.
2. Install:• Torsion spring "1"
To kick shaft "2".
Make sure the stopper "a" of the tor-
sion spring fits into the hole "b" on the
kick shaft.
3. Install:• Spring guide "1"
Slide the spring guide into the kick
shaft, make sure the groove "a" in the
spring guide fits on the stopper of the
torsion spring.
4. Install:• Kick shaft assembly "1"
• Washer "2"
• Apply the molybdenum disulfide
grease on the contacting surfaces
of the kick shaft stopper "a" and kick
shaft ratchet wheel guide "3".
• Apply the engine oil on the kick shaft.
• Slide the kick shaft assembly into the crankcase and make sure the
kick shaft stopper "a" fits into the
kick shaft ratchet wheel guide.
5. Hook:• Torsion spring "1"
Turn the torsion spring clockwise and
hook into the proper hole "a" in the
crankcase.Bolt (shift guide):
10 Nm (1.0 m•kg, 7.2
ft•lb)

5-47
KICK SHAFT AND SHIFT SHAFT
INSTALLING THE KICK IDLE
GEAR
1. Install:• Kick idle gear "1"
• Washer "2"
• Circlip "3"
• Apply the engine oil on the kick idle gear inner circumference.
• Install the kick idle gear with its de- pressed side "a " toward you.

5-48
AC MAGNETO AND STARTER CLUTCH
AC MAGNETO AND STARTER CLUTCH
REMOVING THE AC MAGNETO AND STARTER CLUTCHOrder Part name Q'ty Remarks Drain the engine oil. Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Seat and fuel tank Refer to "REMOVING THE SEAT, FUEL
TANK AND SIDE COVERS" section in the
CHAPTER 3.
Disconnect the AC magneto lead.
1 Shift pedal 1
2 Cover (torque limiter) 1
3 Torque limiter 1 Do not disassemble.
4 Crankcase cover (left) 1
5 Gasket 1
6 Dowel pin 2
7* Nut (rotor) 1 Refer to NOTE.
8 Rotor 1 Refer to removal section.
9 Woodruff key 1
10 Starter clutch drive gear 1
11 Starter clutch assembly cover 1