2010 YAMAHA WR 250F torque

2-17
TIGHTENING TORQUES
GENERAL TORQUE
SPECIFICATIONS
This chart specifies torque for stan-
dard fasteners with standard I.S.O.
pitch threads. Torque specifications
for special components or assem-
blies are included in the applicable
sections of this book. To avoid war-
page, tighten multi-fastener assem-
blies in a crisscross fashion, in
progressive stages, until full torque is
reached. Unless otherwise specified,
torque specifications call for clean,
dry threads. Components should be
at room temperature.A. Distance between flats
B. Outside thread diameter
DEFINITION OF UNITS
A
(Nut) B
(Bolt
) TORQUE SPECIFI-
CATION
Nm m•kg ft•lb
10
mm 6 mm 6 0.6 4.3
12
mm 8 mm 15 1.5 11
14
mm 10
mm 30 3.0 22
17
mm 12
mm 55 5.5 40
19
mm 14
mm 85 8.5 61
22
mm 16
mm 130 13 94
Unit
Read Definition Measure
mm
millimeter 10-3 meterLength
cmcentimeter 10-2 meterLength
kgkilogram 103 gramWeight
NNewton 1 kg × m/sec2Force
NmNewton meter N × mTorque
m•kgMeter kilogram m × kg Torque
PaPascalN/m2Pressure
N/mmNewton per millimeter N/mm Spring rate
LLiter—Volume or capacity
cm3Cubic centimeter —Volume or capacity
r/minRevolution per minute —Engine speed

2-18
TIGHTENING TORQUES

3-27
CHASSIS
2. Inspect:• Bearing free playExist play →Replace.
CHECKING AND ADJUSTING THE
STEERING HEAD
1. Place a stand under the engine to raise the front wheel off the
ground. WARNING! Securely
support the vehicle so that
there is no danger of it falling
over.
2. Check: • Steering stemGrasp the bottom of the forks and
gently rock the fork assembly
back and forth.
Free play →Adjust steering head.
3. Check: • Steering smooth actionTurn the handlebar lock to lock.
Unsmooth action →Adjust steer-
ing ring nut.
4. Adjust: • Steering ring nut
Steering ring nut adjustment
steps:
a. Remove the headlight.
b. Remove the handlebar and upper
bracket.
c. Loosen the steering ring nut "1" using the steering nut wrench "2". d. Tighten the steering ring nut "3"
using steering nut wrench "4".
• Apply the lithium soap base grease
on the thread of the steering stem.
• Set the torque wrench to the steer- ing nut wrench so that they form a
right angle.
e. Loosen the steering ring nut one turn.
f. Retighten the steering ring nut us- ing the steering nut wrench.
Avoid over-tightening.
g. Check the steering stem by turn-ing it lock to lock. If there is any
binding, remove the steering stem
assembly and inspect the steer-
ing bearings.
h. Install the washer "5", collar "6", upper bracket "7", washer "8",
steering stem nut "9", handlebar
"10", handlebar upper holder "11"
and headlight "12".
• Install the collar "6" with the larger inside diameter facing downward.
• The handlebar upper holder should be installed with the punched mark
"a" forward.
• Install the handlebar so that the marks "b" are in place on both
sides. • Install the handlebar so that the pro-
jection "c" of the handlebar upper
holder is positioned at the mark on
the handlebar as shown.
• Insert the end of the fuel breather hose "13" into the hole in the steer-
ing stem.
First tighten the bolts on the front
side of the handlebar upper holder,
and then tighten the bolts on the
rear side.
Steering nut wrench:
YU-33975/90890-01403
Steering nut wrench:YU-33975/90890-01403
Steering ring nut (initial
tightening): 38 Nm (3.8 m•kg, 27
ft•lb)
Steering ring nut (final
tightening): 7 Nm (0.7 m•kg, 5.1
ft•lb)
Steering stem nut:
145 Nm (14.5 m•kg, 105
ft•lb)
Handlebar upper holder:
28 Nm (2.8 m•kg, 20
ft•lb)
Pinch bolt (upper brack-
et): 21 Nm (2.1 m•kg, 15
ft•lb)
Headlight: 7 Nm (0.7 m•kg, 5.1
ft•lb)

4-9
CHASSIS
SUSPENSION SETTING (FRONT FORK)
• If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to the adjustment procedure gi ven in the same chart.
• Before any change, set t he rear shock absorber sunken length to the standard figure 90–100 mm (3.5–3.9 in).
SymptomSection
Check Adjust
Jump Large
gap Medi-
um
gap Small
gap
Stiff over entire
range ○○○ Compression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil level (oil amount) Decrease oil level by about 5–10 mm (0.2–0.4 in).
Spring Replace with soft spring.
Unsmooth move-
ment over entire
range ○○○○ Outer tube
Check for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Inner tube
Under bracket tighten-
ing torque Retighten to specified torque.
Poor initial move-
ment ○Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil seal Apply grease in oil seal wall.
Soft over entire
range, bottoming
out ○○ Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Oil level (oil amount) Increase oil level by about 5–10 mm (0.2–0.4 in).
Spring Replace with stiff spring.
Stiff toward stroke
end ○
Oil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke
end, bottoming out ○
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial move-
ment ○○○○
Compression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture ○○Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Rebound damping Turn adjuster counterclockwise (about 2 clicks) to decrease damping.
Balance with rear end Set sunken length for 95–100 mm (3.7–3.9 in) when one passenger is astride seat (lower rear
posture).
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
"Obtrusive" front,
tending to upper
front posture ○○Compression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 90–95 mm (3.5–3.7 in) when one passenger is astride seat (upper rear
posture).
Spring Replace with soft spring.
Oil level (oil amount) Decrease oil level by about 5–10 mm (0.2–0.4 in).

5-18
CAMSHAFTS
The camshafts should be installed
onto the cylinder head so that the
punch mark "c" on the exhaust cam-
shaft and the punch mark "d" on the
intake camshaft must align with the
cylinder head surface, as shown in
the illustration.
Do not turn the crankshaft during
the camshaft installation. Damage
or improper valve timing will re-
sult.
d. Install the clips, camshaft caps "4"
and bolts (camshaft cap) "5".
• Before installing the clips, cover the cylinder head with a clean rag to
prevent the clips from into the cylin-
der head cavity.
• Apply the molybdenum disulfide oil on the thread of the bolts (camshaft
cap).
• Tighten the bolts to the specified torque in two or three steps in the
proper tightening sequence as
shown.
The bolts (camshaft cap) must be
tightened evenly, or damage to the
cylinder head, camshaft caps, and
camshaft will result.
2. Install:• Timing chain tensioner
Installation steps:
a. While pressing the tensioner rod lightly with fingers, use a thin
screwdriver and wind the tension-
er rod up fully clockwise.
b. With the rod fully wound and the chain tensioner UP mark "a" fac-
ing upward, install the gasket "1"
and the timing chain tensioner "2",
and tighten the bolt "3" to the
specified torque.
c. Release the screwdriver, check the tensioner rod to come out and
tighten the gasket "4" and the cap
bolt "5" to the specified torque.
3. Turn:
• CrankshaftCounterclockwise several turns.
4. Check:
• Rotor T.D.C. markAlign with the crankcase align
mark.
• Camshaft match marks Align with the cylinder head sur-
face.
Out of alignment →Adjust. 5. Install:
• Timing mark accessing screw "1"
• Crankshaft end accessing screw "2"
6. Install: • Timing chain guide (top side) "1"
• Cylinder head cover gasket "2"
• Cylinder head cover "3"
• Bolt (cylinder head cover) "4"
Apply the sealant on the cylinder
head cover gasket.
7. Install:• Cylinder head breather hose
• Spark plug
Bolt (camshaft cap):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Bolt (timing chain ten-
sioner):10 Nm (1.0 m•kg, 7.2
ft•lb)
Tensioner cap bolt: 7 Nm (0.7 m•kg, 5.1
ft•lb)
Bolt (cylinder head cov-
er): 10 Nm (1.0 m•kg, 7.2
ft•lb)
YAMAHA Bond No. 1215
(ThreeBond
® No. 1215):
90890-85505
Spark plug: 13 Nm (1.3 m•kg, 9.4
ft•lb)

5-49
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 TIP.
8 Rotor 1 Refer to removal section.
9 Woodruff key 1
10 Starter clutch drive gear 1
11 Starter clutch assembly cover 1

5-51
AC MAGNETO AND STARTER CLUTCH
REMOVING THE ROTOR
1. Remove:• Nut (rotor) "1"
• Washer
Use the sheave holder "2".
2. Remove: • Rotor "1"Use the rotor puller "2".
REMOVING THE STARTER
CLUTCH
1. Remove: • Starter clutch a ssembly cover "1"
Insert a thin screwdriver or the like
under the convexity "a" and remove
the starter clutch assembly cover by
prying it gently to void damage to the
cover.
2. Remove:
• Starter clutch "1"
Using a thin screwdriver or the like,
remove the plate "a" while prying it
upward little by little.
CHECKING THE AC MAGNETO
1. Inspect:
• Rotor inner surface "a"
• Stator outer surface "b"Damage →Inspect the crankshaft
runout and crankshaft bearing.
If necessary, replace AC magneto
and/or stator.
CHECKING THE WOODRUFF KEY
1. Inspect: • Woodruff key "1"
Damage →Replace.
CHECKING THE STARTER
CLUTCH
1. Check: • Starter clutchDamage/wear →Replace.
2. Check:
• Idle gear
• Starter clutch drive gearPitting/burrs/chips/roughness/
wear →Replace the defective
parts. 3. Check:
• Starter clutch operation
a. Install the starter clutch drive gear "1" onto the starter clutch "2" and
hold the starter clutch.
b. When turning the starter clutch
drive gear counterclockwise "B",
the starter clutch and the starter
clutch drive gear should engage.
If the starter clutch drive gear and
starter clutch do not engage, the
starter clutch is faulty and must be
replaced.
c. When turning the starter clutch drive gear clockwise "A", it should
turn freely. If the starter clutch
drive gear does not turn freely, the
starter clutch is faulty and must be
replaced.
CHECKING THE TORQUE LIMITER
1. Check:• Torque limiter
Damage/wear →Replace.
INSTALLING THE AC MAGNETO
AND STARTER CLUTCH
1. Install: • Stator "1"
• Bolt (stator) "2"
Sheave holder:
YS-1880-A/90890-
01701
Rotor puller: YM-04141/90890-04141
Bolt (stator):7 Nm (0.7 m•kg, 5.1
ft•lb)

5-53
AC MAGNETO AND STARTER CLUTCH
10. Install:• Dowel pin
• Gasket [crankcase cover (left)]
• Crankcase cover (left) "1"
• Bolt [crankcase cover (left)] "2"
• Bolt [crankcase cover (left)] "3"
Tighten the bolts in stage, using a
crisscross pattern.
11. Install:• Washer "1"
• Torque limiter "2"
• Washer "3"
Apply the engine oil to the shaft and
washers.
12. Install:• O-ring
• Cover (idle gear 1) "1"
•Bolt "2"
• Apply the lithium soap base grease on the O-ring.
• Install the cover (idle gear 1) with its
mark "a" facing upward.
13. Connect:• AC magneto lead
Refer to "CABLE ROUTING DIA-
GRAM" section in the CHAPTER
2.
14. Install: • Shift pedal "1"
• Bolt (shift pedal) "2"
When installing the shift pedal onto
the shift shaft, be sure that the center
of the shift pedal is about 1.4 mm
(0.06 in) "a" above the top of the foot-
rest.
Bolt [crankcase cover
(left)]: 10 Nm (1.0 m•kg, 7.2
ft•lb)
Bolt [crankcase cover
(left)]: 12 Nm (1.2 m•kg, 8.7
ft•lb)
Bolt: 10 Nm (1.0 m•kg, 7.2
ft•lb)
E
Bolt (shift pedal):
12 Nm (1.2 m•kg, 8.7
ft•lb)