light YAMAHA WR 250F 2017 Owner's Manual

ELECTRICAL SYSTEM
3-41
3. Adjust:
• Engine idling speed
Refer to “ADJUSTING THE ENGINE
IDLING SPEED” on page 3-18.
4. Check:
• Ignition timing
Check whether the alignment mark “a” on
the left crankcase cover is within the firing
range “b” on the rotor.
Incorrect firing range  Check rotor and
Crankshaft position sensor.
5. Install:
• Timing mark accessing screw
EAS2GBB133CHECKING AND CHARGING THE BATTERY
Refer to “CHECKING AND CHARGING THE
BATTERY” on page 9-69.
EAS2GBB134REPLACING THE HEADLIGHT BULBEWA
WARNING
Since the headlight bulb gets extremely hot,
keep flammable products and your hands
away from the bulb until it has cooled down.
1. Remove:
• Headlight unit bolt “1”
TIP
After you have removed the headlight unit
bolts, lift and remove the headlight unit.
2. Remove:
• Headlight coupler “1”
• Bulb cover “2”
3. Remove:
• Headlight bulb “1” Timing light
90890-03141
Timing light
YU-03141
Digital tachometer
90890-06760
Digital tachometer
YU-39951-B
Timing mark accessing screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
2
1
3
ba
T R..
11
1
2
1

ELECTRICAL SYSTEM
3-42
4. Install:
• Headlight bulb
Fasten the new headlight bulb with the
headlight bulb holder.
ECA
NOTICE
Avoid touching the glass part of the head-
light bulb to keep it free from oil, otherwise
the transparency of the glass, the life of the
bulb and the luminous flux will be adversely
affected. If the headlight bulb gets soiled,
thoroughly clean it with a cloth moistened
with alcohol or lacquer thinner.
5. Install:
• Bulb cover
• Headlight coupler
6. Install:
• Headlight unit
Headlight unit bolt
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
New
T R..

GENERAL CHASSIS
5-2
Removing the headlight assembly and multi-function meter
Order Job/Parts to remove Q’ty Remarks
1 Headlight body 1
2 Headlight coupler 1 Disconnect.
3 Headlight unit 1
4 Speed sensor coupler 1 Disconnect.
5 Multi-function meter coupler 2 Disconnect.
6 Multi-function meter optional switch coupler 1 Disconnect.
7 Indicator light coupler 1 Disconnect.
8 Multi-function meter 1
9 Meter bracket 1
For installation, reverse the removal proce-
dure.
4(2)
6 7 8
9
5
1
3
2
21 Nm (2.1 m kgf, 15 ft Ibf)T.R.3.8 Nm (0.38 m kgf, 2.8 ft Ibf)T.R.
3.8 Nm (0.38 m kgf, 2.8 ft Ibf)T.R.
21 Nm (2.1 m kgf, 15 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.

HANDLEBAR
5-36
NOTICE
• First, tighten the bolts on the front side of
the upper handlebar holder, and then on
the rear side.
• Turn the handlebar all the way to the left
and right. If there is any contact with the
fuel tank, adjust the handlebar position.
3. Tighten:
• Lower handlebar holder nut
4. Install:
• Handlebar grip “1”
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Slightly coat the handlebar left end with a
rubber adhesive.
b. Install the handlebar grip on the handlebar
by pressing the grip from the left side.
c. Wipe off any excess adhesive with a clean
cloth.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Install the handlebar grip to the handlebar so
that the line “a” between the two arrow marks
faces straight upward.
2
1
1
a
3
4
Lower handlebar holder nut
40 Nm (4.0 m·kgf, 29 ft·lbf)
T R..

HANDLEBAR
5-37
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5. Install:
• Engine stop switch “1”
• Clutch lever “2”
• Clutch lever holder “3”
•Clamp “4”
TIP
• The engine stop switch, the clutch lever, and
the clutch lever holder should be installed ac-
cording to the dimensions shown.
• Pass the engine stop switch lead through the
middle of the clutch lever holder.
6. Install:
• Right grip “1”
• Collar “2”
Apply adhesive to the tube guide “3”.
TIP
• Before applying the adhesive, wipe off grease
or oil on the tube guide surface “a” with a lac-
quer thinner.
• Install the grip to the tube guide so that the
grip match mark “b” and tube guide slot “c”
form the angle as shown.7. Install:
• Rubber cover “1”
• Throttle grip “2”
TIP
Apply the lithium-soap-based grease on the
throttle grip sliding surface.
8. Install:
• Throttle cables “1”
TIP
Slightly coat the end of throttle cable and inside
of throttle grip with lithium-soap-based grease.
Then, mount the throttle grip onto the handle-
bar. Engine stop switch screw
0.5 Nm (0.05 m·kgf, 0.36 ft·lbf)
Clutch lever holder bolt
3.8 Nm (0.38 m·kgf, 2.8 ft·lbf)
T R..
64
1b
c
3 64

STEERING HEAD
5-53
EAS2GBB203
STEERING HEAD
Removing the lower bracket
Order Part name Q’ty Remarks
Refer to “CHECKING AND ADJUSTING
THE STEERING HEAD” on page 3-37.
Use a suitable stand to raise the front wheel
off the ground.
Headlight assembly/multi-function meter/front
fenderRefer to “GENERAL CHASSIS” on page 5-1.
Handlebar Refer to “HANDLEBAR” on page 5-33.
1 Front fender 1
2 Steering stem nut 1
3 Front fork leg (s) 2 Refer to “FRONT FORK” on page 5-40.
4 Upper bracket 1
5 Steering ring nut 1
6 Lower bracket 1
7 Bearing race cover 1
8 Upper bearing 1
9 Bearing (lower side) 1
10 Bearing races 2
2
4
5
7
3
(2)(2)
(2)
(2) (2)
1
6
8
9
10
LS
LS
T
.R.21 Nm (2.1 mlbf) kgf, 15 ft
T
.R.21 Nm (2.1 mlbf) kgf, 15 ft
T
.R.21 Nm (2.1 mlbf) kgf, 15 ft
T
.R.21 Nm (2.1 mlbf) kgf, 15 ft
T
.R.3.8 Nm (0.38 mlbf) kgf, 2.8 ft
T
.R.3.8 Nm (0.38 mlbf) kgf, 2.8 ft
T
.R.9 Nm (0.9 mlbf) kgf, 6.5 ft
T
.R.7 Nm (0.7 mlbf) kgf, 5.1 ftT
.R.7 Nm (0.7 mlbf) kgf, 5.1 ft
T
.R.10 Nm (1.0 mlbf) kgf, 7.2 ft
T
.R.145 Nm (14.5 mlbf) kgf, 105 ft
T
.R.38 Nm (3.8 mlbf) kgf, 27 ft
7 Nm (0.7 m
lbf) kgf, 5.1 ft
*
*

ENGINE REMOVAL
6-7
EAS2GBB230REMOVING THE ENGINE
1. Remove:
• Pivot shaft “1”
TIP
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar diameter into the other side of
the swingarm to support it.
2. Remove:
• Engine “1”
From the right side.
TIP
• Make sure that the couplers, the hoses, and
the cables are disconnected.
• Lift up the engine, and remove this from its
lower part toward the right of the chassis.
EAS2GBB231CLEANING THE SPARK ARRESTEREWA
WARNING
• Be sure the exhaust pipe and muffler are
cool before cleaning the spark arrester.
• Do not start the engine when cleaning the
exhaust system.
1. Remove:
• Muffler cap screws “1”
2. Remove:
• Spark arrester bolts “1”
3. Remove:
• Tail pipe “1”
• Tail pipe gasket “2”
• Spark arrester “3”
Pull the spark arrester out of the muffler.
• Spark arrester gasket “4”
4. Clean:
• Spark arrester
Tap the spark arrester lightly, then use a
wire brush to remove any carbon deposits.
1

CAMSHAFT
6-16
c. Install the dowel pins and the camshaft
caps.
TIP
• Tighten the camshaft cap bolts in a crisscross
pattern from innermost to outer caps.
• Do not turn the camshaft when measuring the
camshaft journal-to-camshaft cap clearance.
d. Remove the camshaft caps and then mea-
sure the width of the Plastigauge® “1”.
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5. Measure:
• Camshaft journal diameter “a”
Out of specification  Replace the cam-
shaft.
Within specification  Replace the cylinder
head and the camshaft caps as a set.
EAS2GBB240CHECKING THE TIMING CHAIN AND CAM-
SHAFT SPROCKET
1. Check:
•Timing chain
Damage/stiffness  Replace the timing
chain and camshaft as a set.2. Check:
• Camshaft sprocket
More than 1/4 tooth wear “a”  Replace the
camshaft and the timing chain as a set.
EAS2GBB241CHECKING THE TIMING CHAIN TENSION-
ERS
1. Check:
• Timing chain tensioner
Crack/damage  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. While pressing the tensioner rod lightly with
your fingers, use a thin screwdriver “1” to
wind the tensioner rod up fully clockwise.
b. When releasing the screwdriver by pressing
lightly with your fingers, make sure that the
tensioner rod will come out smoothly.
c. If not, replace the tensioner assembly.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
Camshaft cap bolts
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Camshaft journal diameter
21.959–21.972 mm (0.8645–
0.8650 in)
T R..
1
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
a
b1
2

CAMSHAFT
6-18
ECA33DD030
NOTICE
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
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. While pressing the tensioner rod lightly with
your fingers, use a thin screwdriver to wind
the tensioner rod up fully clockwise.
b. With the tensioner rod fully wound and the
chain tensioner UP mark “a” facing upward,
install the gasket “1” and the timing chain
tensioner “2” and tighten the bolt “3”.c. Release the screwdriver, check that the ten-
sioner rod comes out smoothly, and tighten
the gasket “4” and the cap bolt “5”.
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3. Turn:
• Crankshaft
Counterclockwise several turns.
4. Check:
• Top dead center (TDC) mark on the rotor
Align with the crankcase alignment mark.
• Camshaft match marks
Align with the cylinder head surface.
Out of alignment  Adjust.
5. Install:
• Timing chain guide (top side) “1”
• Cylinder head cover gasket “2”
• Cylinder head cover “3”
• Bolt (cylinder head cover) “4”
TIP
Before installation, apply the sealant to the cyl-
inder head cover gasket. Bolt (timing chain tensioner)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
3
4
8
7
15
26
E
T R..
Tensioner cap bolt
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
Bolt (cylinder head cover)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Yamaha bond No.1215
90890-85505
(Three bond No.1215®)
T R..
4
5
T R..
4
4
3
21

VALVES AND VALVE SPRINGS
6-30
EAS2GBB255INSTALLING THE VALVES
1. Clean:
• Valve stem end
2. Lubricate:
• Valve stem “1”
• Valve stem seal “2”
3. Install:
• Spring seat “1”
• Valve stem seal “2”
•Valve “3”
• Valve spring “4”
• Valve spring retainer “5”
(to the cylinder head)
TIP
• Make sure each valve is installed in its original
place.
• Install the valve springs with the larger pitch
“a” facing up.4. Install:
• Valve cotter “1”
TIP
Install the valve cotters by compressing the
valve spring with the valve spring compressor
“2” and the valve spring compressor adapter
“3”.
5. To fasten the valve cotters onto the valve
stem, lightly tap the valve tip with a soft-face
hammer.
ECA
NOTICE
Hitting the valve tip with excessive force
could damage the valve. Recommended lubricant
Molybdenum disulfide oil
New
b. Smaller pitch
Valve spring compressor
90890-04019
Valve spring compressor
YM-04019
Valve spring compressor attach-
ment
90890-04108
Valve spring compressor adapter
22 mm
YM-04108