2017 YAMAHA WR 250F air filter

ENGINE
3-15
4. Check:
• Air filter element
Damage  Replace.
5. Apply:
• Yamaha foam air filter oil or other quality
foam air filter oil
TIP
Squeeze out the excess oil. Element should be
wet but not dripping.
6. Install:
• Air filter guide “1” (to the air filter element)
• Air filter element “2”
• Air filter mounting bolt “3”
7. Install:
• Air filter case cover “1”
TIP
Align the air filter case cover groove “a” with the
air filter case edge “b”.8. Install:
• Fuel tank cap cover
EAS2GBB092CHECKING THE THROTTLE BODY JOINT
1. Check:
• Throttle body joint
Refer to “CHECKING THE THROTTLE
BODY JOINT” on page 8-10.
EAS2GBB093CHECKING THE BREATHER HOSES
1. Check:
• Breather hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.
ECA
NOTICE
Make sure the cylinder head breather hose
is routed correctly.
EAS2GBB094CHECKING THE EXHAUST SYSTEM
1. Remove:
• Exhaust pipe protector
2. Check:
• Exhaust pipe 1
• Exhaust pipe 2
• Silencer
Crack/damage  Replace.
Refer to “ENGINE REMOVAL” on page 6-1.
• Exhaust gas
Leaks  Replace the gasket.
Refer to “ENGINE REMOVAL” on page 6-1. Oil application quantify
50 g
Air filter mounting bolt
2.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
T R..
31
2
a
b 1
1
1
1

ENGINE
3-18
d. Install the oil strainer.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
6. Install:
•Gasket
• Drain bolt
7. Pour the specified amount of engine oil into
the oil filler cap hole.
8. Install:
• Oil filler cap
9. Check:
• Oil level
Refer to “CHECKING THE ENGINE OIL
LEVEL” on page 3-16.
10.Check:
• Engine oil pressure
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Slightly loosen the oil pressure check bolt
“1”.
EWA
WARNING
When the engine is started with the check
bolt removed, oil will spout; therefore, al-
ways loosen it before the checkup.b. Start the engine and keep it idling until oil
starts to seep from the oil pressure check
bolt.
EWA
WARNING
Always keep the engine idling speed during
the checkup without increasing the engine
speed.
ECA
NOTICE
If no engine oil seeps out after one minute,
immediately turn the engine off so it will not
seize.
c. If no engine oil seeps out, check the engine
oil for leaks, and the engine oil passage and
the oil pump for damage.
d. Check the oil pressure again.
e. Tighten the oil pressure check bolt.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GBB098ADJUSTING THE ENGINE IDLING SPEED
TIP
• Because the air pressure is lower at high alti-
tudes, the air-fuel mixture will become richer.
If the idling speed is low, turn the starter knob/
idle screw a few clicks counterclockwise to in-
crease the speed before the adjustment.
• Before adjusting the engine idling speed,
make sure that the air filter element is not
clogged, the engine compression is proper,
and the throttle grip free play is proper.
• Adjust the engine idling speed with the starter
knob/idle screw pushed in completely. Oil strainer bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Drain bolt
20 Nm (2.0 m·kgf, 14 ft·lbf)
Engine oil quantity
Oil change
0.83 L (0.88 US qt, 0.73 Imp.qt)
With oil filter removal
0.85 L (0.90 US qt, 0.75 Imp.qt)
Quantity (disassembled)
1.10 L (1.16 US qt, 0.97 Imp.qt)
T R..
New
T R..
Oil pressure check bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
T R..

ENGINE REMOVAL
6-3
Removing the electronic parts
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case cover
1 Rectifier/regulator 1
2ECU 1
3 Ignition coil 1
4 Neutral switch 1
5 AC magneto coupler 1 Disconnect.
6 Crankshaft position sensor coupler 1 Disconnect.
7 Coolant temperature sensor coupler 1 Disconnect.
For installation, reverse the removal proce-
dure.
T.R.
T.R.
T.R.T.R.
7 3
6
5
142
LT
New
LS

ENGINE REMOVAL
6-4
Removing the engine
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 6-1.
Air filter case Refer to “THROTTLE BODY” on page 8-7.
Throttle body Refer to “THROTTLE BODY” on page 8-7.
Clutch cable Refer to “CLUTCH” on page 6-42.
Shift pedal Refer to “SHIFT SHAFT” on page 6-54.
Starter motorRefer to “ELECTRIC STARTER” on page 6-
37.
1 Engine guard 1
2 Brake pedal 1
3Spring 1
4 Cylinder head breather hose 1
New
New
LS
M
8
8
7
6
13
45
New
1 12
3
2
1110
9
55 Nm (5.5 m kgf, 40 ft Ibf)T.R.

RADIATOR
7-1
EAS2GBB328
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, service engineers, etc.). Those who have little knowl-
edge and skill concerning servicing are requested not to undertake inspection, adjustment, disas-
sembly, or reassembly only by reference to this manual. It may lead to servicing trouble and
mechanical damage.
EAS2GBB329
RADIATOR
Removing the radiator
Order Part name Q’ty Remarks
CoolantDrain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case Refer to “THROTTLE BODY” on page 8-7.
1 Radiator guard 2
2 Radiator hose clamp 8 Loosen.
3 Radiator fan 1
12
13
New
New
New
LS
LS
3
458 Nm (0.8 m kgf, 5.8 ft Ibf)T.R.
6
7
89
10
112
2
2
2 22 2
1 1

THROTTLE BODY
8-7
EAS2GBB351
THROTTLE BODY
Removing the throttle body
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
ECU Refer to “ENGINE REMOVAL” on page 6-1.
Ignition coil Refer to “ENGINE REMOVAL” on page 6-1.
1 Intake air temperature sensor coupler 1 Disconnect.
2 Breather hose 3 1
3 Air filter case 1
4 Fuel injector coupler 1 Disconnect.
5 Intake air pressure sensor coupler 1 Disconnect.
6 Throttle position sensor coupler 1 Disconnect.
7 Throttle cable cover 1
8 Throttle cable 2
3
1
2
7
11
12
10
9
4
8
6
5
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
3.0 Nm (0.30 m kgf, 2.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

IGNITION SYSTEM
9-4
EAS2GBB359TROUBLESHOOTING
The ignition system fails to operate (no spark or intermittent spark).
TIP
Before troubleshooting, remove the following part (s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank
5. Air filter case cover
1. Check the fuse.
Refer to “CHECKING THE FUSES”
on page 9-68.NG 
Replace the fuse(s).
OK 
2. Check the battery.
Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 9-69.NG 
• Clean the battery terminals.
• Recharge or replace the battery.
OK 
3. Check the spark plug.
Refer to “CHECKING THE SPARK
PLUG” on page 3-40.NG 
Re-gap or replace the spark plug.
OK 
4. Check the ignition spark gap.
Refer to “CHECKING THE IGNI-
TION SPARK GAP” on page 9-73.OK 
The ignition system is normal.
NG 
5. Check the ignition coil.
Refer to “CHECKING THE IGNI-
TION COIL” on page 9-74.NG 
Replace the ignition coil.
OK 
6. Check the crankshaft position sen-
sor.
Refer to “CHECKING THE CRANK-
SHAFT POSITION SENSOR” on
page 9-75.NG 
Replace the stator assembly.
OK 
7. Check the engine stop switch.
Refer to “CHECKING THE
SWITCHES” on page 9-64.NG 
Replace the engine stop switch.
OK 

ELECTRIC STARTING SYSTEM
9-10
EAS2GBB362TROUBLESHOOTING
The starter motor fails to turn.
TIP
Before troubleshooting, remove the following part (s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank
5. Air filter case cover
1. Check the fuse.
Refer to “CHECKING THE FUSES”
on page 9-68.NG 
Replace the fuse(s).
OK 
2. Check the battery.
Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 9-69.NG 
• Clean the battery terminals.
• Recharge or replace the battery.
OK 
3. Check the starter motor operation.
Refer to “CHECKING THE START-
ER MOTOR OPERATION” on page
9-76.OK 
Starter motor is OK. Perform the electric
starting system troubleshooting, starting
with step 5.
NG 
4. Check the starter motor.
Refer to “CHECKING THE START-
ER MOTOR” on page 6-39.NG 
Repair or replace the starter motor.
OK 
5. Check the relay unit (Starting circuit
cut-off relay).
Refer to “CHECKING THE RE-
LAYS” on page 9-72.NG 
Replace the relay unit.
OK 
6. Check the diode.
Refer to “CHECKING THE DIODE”
on page 9-73.NG 
Replace the diode.
OK 
7. Check the starter relay.
Refer to “CHECKING THE RE-
LAYS” on page 9-72.NG 
Replace the starter relay.
OK 