2015 YAMAHA WR 250F sensor

CABLE ROUTING DIAGRAM
2-34
1. Clutch cable
2. Throttle cable (return)
3. Throttle cable (pull)
4. Engine stop switch lead
5. Coupler for connecting optional part
6. Engine stop switch coupler
7. Rectifier/regulator coupler
8. AC magneto lead
9. Starter knob/idle screw
10. Starter motor lead
11. Radiator fan fuse
12. Taillight
13. Headlight relay (yellow tape)
14. Starting circuit cut-off relay (no identification
tape)
15. Diode
16. Holder plate
17. Left of the vehicle:radiator fan motor relay (blue
tape)
Right of the vehicle:main relay (red tape)
18. Neutral switch lead
19. Engine bracket
20. Front engine bracket
21. Plastic locking tie
22. Radiator hose
23. Neutral switch coupler
24. Crankshaft position sensor coupler
25. Tension arm
26. Wire harness
27. Tank rail
28. Rectifier/regulator
29. Rectifier/regulator bracket
30. Rear frame
31. Side cover 5
32. Crankcase cover
33. Crankcase
34. Lead holder
35. Frame
A. Pass the engine stop switch lead between the
frame and the cable holder.
B. Insert the coupler for connecting optional part into
the connector, and fix it to the bracket.
C. Insert and fix the engine stop switch coupler to
the bracket.
D. Insert and fix the rectifier/regulator coupler to the
bracket.
E. Pass the AC magneto lead to the front of the ve-
hicle beyond the starter knob/idle screw and to
the rear of the vehicle beyond the radiator. No
pinch is allowed between the radiator and the
tension arm.
F. Place the rear grommet of the starter motor lead
matching the rear end of the side cover.
G. Insert the radiator fan motor fuse into the protru-
sion of the holder plate.
H. Place the diode on top of the rear fender on the
inner side of the rear frame.
I. Bring the neutral switch lead into line with the
crankcase cover with no sag allowed.
J. Route the AC magneto lead under the starter
clutch cover.
K. Pass the neutral switch lead to the inside of the
front engine bracket (the side of the vehicle).
L. Insert the plastic locking tie into the bracket hole
and clamp the clutch cable. Clamp it so that the
lock of the plastic locking tie faces downward,
and then cut off the end of the plastic locking tie.
M. Pass the clutch cable with no downward sag al-
lowed.N. Place the grommet of the clutch cable so that it
contacts the radiator hose. Route the clutch cable
outside the neutral switch lead, AC magneto lead
and starter motor lead.
O. Route each lead so that the leads are not pinched
between the radiator hose and the frame.
P. 40 mm (1.57 in)
Q. Clamp the clutch cable, AC magneto lead, neu-
tral switch lead and starter motor lead by the plas-
tic locking tie. Make sure that they are clamped at
the positioning tapes in the clutch cable and the
starter motor lead. Make the lock on the plastic
locking tie face the front of the vehicle, and cut
the end.
R. Clamp the starter motor lead to the inside of the
tension arm with a plastic locking tie. Clamp it so
that the lock of the plastic locking tie faces up-
ward and outward, and do not cut off the end of
the plastic locking tie. Route the lead so that there
is no slack at the bottom from the clamp position
onwards.
S. After connecting the neutral switch coupler, at-
tach the coupler cover.
T. After connecting the crankshaft position sensor
coupler, attach the coupler cover.
U. Pass the rectifier/regulator lead to the inside of
the tension arm (the side of the vehicle).
V. Pass the main harness to the front of the radiator
hose (the front of the vehicle), and to the inside of
the clutch cable (the side of the vehicle).
W. Pass the engine stop switch lead between the
coupler for connecting optional part and the tank
rail, with the lead on the main harness side facing
the top of the vehicle.
X. Insert the starter motor lead completely into the
end of the side cover 5.
Y. Clamp the clutch cable at the front of the lead (the
front of the vehicle).
Z. Insert the clip of the plastic locking tie into the
frame. Face the lock of the plastic locking tie for-
ward, and then cut off the end.

CABLE ROUTING DIAGRAM
2-36
1. Clamp
2. Cylinder head breather hose
3. Throttle position sensor lead
4. Joint coupler
5. Intake air temperature sensor coupler
6. Intake air pressure sensor lead
7. Wire harness
8. Injector lead
9. Throttle body
10. Injector coupler
11. Starter motor lead
12. Plastic band
13. Fuel sender coupler
14. High tension cord
15. Spark plug cap
16. Cylinder head cover
17. Fuel hose
18. Fuel sender
19. Sub-wire harness
20. Crankcase breather hose
21. Radiator breather hose
22. Radiator hose
23. Down tube
24. Starter motor
25. Neutral switch lead
26. AC magneto lead
27. Clutch cable
28. Radiator
29. Air filter case breather hose
30. Breather hose clamp
31. Grommet (high tension cord)
32. ECU
33. Air filter case
34. Sub-wire harness coupler
35. Engine bracket
A. Fix the wire harness, clutch switch lead and start
switch lead by the plastic clamp, and insert the
projection of the plastic clamp into the hole in the
sheet metal of the radiator.
B. Route each lead so that the leads are not pinched
between the tank rail and air filter joint.
C. Insert the projection of the wire harness into the
hole in the frame.
D. Route the cylinder head breather hose without it
crossing the starter motor lead.
E. Pass the cylinder head breather hose between
the throttle cable and rectifier/regulator lead.
F. Connect the sub-wire harness to the wire har-
ness.
G. Pass the high tension cord above the fuel hose.
H. ±10°
I. Install the spark plug cap with this facing the right
of the vehicle.
J. Push the spark plug cap home, where there shall
be no gap between it and the cylinder head cover.
K. Pass the radiator breather hose between the
down tubes.
L. Apply adhesive to the slit and inside of the grom-
met, and then fix the grommet according to the
specified dimensions.
M. Pass the sub-wire harness between the ECU and
the air filter case.
N. Insert the coupler of the sub-wire harness into the
rib of the air filter case.
O. Route the radiator breather hose through be-
tween the radiator hose, down tube and engine
bracket.

CABLE ROUTING DIAGRAM
2-38
1. Cable guide
2. Speed sensor lead
3. Joint coupler
4. Ground lead
5. Throttle position sensor lead
6. Throttle position sensor coupler
7. Radiator breather hose
8. Cylinder head breather hose
9. Crankcase breather hose
10. Radiator hose
11. Fuel hose
12. Engine ground lead
13. Coolant temperature sensor coupler
14. Radiator fan motor lead
15. Intake air pressure sensor coupler
16. Intake air temperature sensor coupler
17. Start switch coupler
18. Radiator fan motor coupler
19. Clutch switch coupler
20. Air filter case
21. Plate
22. Bracket
A. Pass the wire harness under the start switch lead
and clutch switch lead.
B. Insert and fix the joint coupler to the plate. After
fixing it, attach the cover.
C. Pass the throttle position sensor lead to the out-
side of the tension arm (the outside of the vehi-
cle).
D. After connecting the throttle position sensor cou-
pler, attach the cover.
E. Pass the radiator breather hose to the outside of
the tension arm and the throttle position sensor
lead (the outside of the vehicle), and to the inside
of the radiator hose (the side of the vehicle).
F. 45°
G. Install the engine ground lead within a range of
45° from a location where it will not run over the
step difference of the radiator hose joint. Both
sides of the engine ground lead terminal can be
used.
H. Attach the coupler cover to the coolant tempera-
ture sensor coupler.
I. Pass the radiator fan motor lead to the inside of
the tension arm (the side of the vehicle).
J. Install the ground lead terminal between the plate
and the bolt.
K. Fix the ground lead terminal to the detent in the
plate. For the ground lead terminal, either side
will do.
L. Detent

CABLE ROUTING DIAGRAM
2-40
1. Battery negative lead
2. Fuel hose
3. Fuel pump coupler
4. Fuel pump lead
5. Resistor
6. Resistor coupler
7. Battery positive lead
8. Lean angle sensor
9. Starter motor lead
10. Radiator fan motor relay (blue tape)
11. Main relay (red tape)
12. Wire harness
13. Ground lead coupler
14. Starter relay coupler
15. Starter relay
16. Cross member
17. Diode
18. Taillight lead
19. Clamp
20. Fuel tank
21. Damper
22. Rear frame
23. Side cover 6
24. Plastic locking tie
A. After connecting the fuel pump coupler, attach
the coupler cover.
B. Pass the fuel hose to the front of the battery.
C. Route the resistor lead to the outside of the leads.
D. Connect the battery positive lead to the starter re-
lay terminal (in the left side of the vehicle).
E. Insert the protruding end of the wire harness into
the battery bracket hole and holder plate hole.
F. After connecting the negative lead coupler, place
it on the right side of the battery.
G. After installing the plastic cover to the starter re-
lay, connect the starter relay coupler.
H. Route the diode under the cross member and
place it on top of the rear fender.
I. Secure the two ends of the taillight coupler with
the starter motor lead.
J. Route the taillight lead so that it does not slack at
the rear of the vehicle.
K. Clamp the taillight lead and insert the clip into the
rear fender. Clamp it so that the lock faces in-
ward, and then cut off the excess end.
L. Route the battery positive lead under the cross
member.
M. Lower end of the rear frame
N. Clamp it so that the lock of the plastic locking tie
faces downward, insert the end into the rear
frame and side cover 6, and then cut off the ex-
cess end. After cutting off the excess end, make
sure that the plastic locking tie does not protrude
from the lower end of the rear frame.
O. Clamp it so that the lock of the plastic locking tie
faces downward, and then pass the end between
the fuel hose and rear frame.
P. Clamp the wire harness at the position of the
white tape.

CABLE ROUTING DIAGRAM
2-42
1. Clutch switch lead
2. Engine stop switch lead
3. Clutch cable
4. Brake hose guide
5. Headlight lead
6. Speed sensor lead
7. Indicator light coupler
8. Meter assembly optional switch coupler
9. Meter assembly coupler
10. Speed sensor coupler
11. Start switch lead
12. Plastic band
13. Throttle cable
14. Front brake hose
A. Route the throttle cable, clutch cable, clutch
switch lead, engine stop switch lead and start
switch lead between the cable guide of the meter
bracket and handle crown. The cables and leads
may be routed in any order.
B. Clamp the wire harness, clutch switch lead and
start switch lead to the meter bracket. The clamp
shall be located at a position where there is no
slack with the handle turned fully to the left.
C. Connect the headlight lead to the headlight.
D. Clamp the start switch lead to the handlebar by
the plastic band.
E. Clamp the engine stop switch lead and clutch
switch lead to the handlebar by the plastic band.
F. 40°±10°
G. Vertical direction
H. Pass the engine stop switch lead under the han-
dlebar.

ELECTRICAL SYSTEM
3-40
2. Attach:
• Timing light “1”
• Digital tachometer “2”
To the high tension code “3”.
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
EAS2GB2135
CHECKING AND CHARGING THE BATTERY
Refer to “CHECKING AND CHARGING THE
BATTERY” on page 9-69.
EAS2GB2136REPLACING 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

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
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.

FRONT WHEEL
5-4
EAS2GB2156
FRONT WHEEL
Removing the front wheel
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
1 Front wheel axle pinch bolt 4 Loosen.
2 Front wheel axle nut 1
3 Front wheel axle 1
4 Front wheel 1
5 Speed sensor 1
6Collar 1
7 Oil seal 1
8 Bearing 2
9 Brake disc 1
For installation, reverse the removal proce-
dure.
12 Nm (1.2 m kgf, 8.7 ft Ibf)T.R.
New
LT
LS
LS
LS
8
7 8
(6)
9
12
1 3
21 Nm (2.1 m kgf, 15 ft Ibf)T.R.
21 Nm (2.1 m kgf, 15 ft Ibf)T.R.
4
90 Nm (9.0 m kgf, 65 ft lbf)T.R.
5
6