2015 YAMAHA WR 250F engine coolant

3
PERIODIC CHECKS AND ADJUSTMENTS
PERIODIC MAINTENANCE............................................................................. 3-1
INTRODUCTION ........................................................................................ 3-1
PERIODIC MAINTENANCE CHART FOR THE EMISSION
CONTROL SYSTEM ................................................................................. 3-1
GENERAL MAINTENANCE AND LUBRICATION CHART ........................ 3-2
MAINTENANCE INTERVALS FOR COMPETITION USE ......................... 3-4
PRE-OPERATION INSPECTION AND MAINTENANCE................................. 3-9
GENERAL INSPECTION AND MAINTENANCE........................................ 3-9
ENGINE.......................................................................................................... 3-10
CHECKING THE COOLANT LEVEL ........................................................ 3-10
CHECKING THE COOLING SYSTEM ..................................................... 3-10
CHANGING THE COOLANT.................................................................... 3-10
CHECKING THE RADIATOR CAP .......................................................... 3-11
CHECKING THE RADIATOR CAP OPENING PRESSURE .................... 3-11
CHECKING THE COOLANT CIRCULATORY SYSTEM FOR LEAKS .... 3-12
ADJUSTING THE CLUTCH LEVER FREE PLAY .................................... 3-12
ADJUSTING THE THROTTLE GRIP FREE PLAY .................................. 3-13
LUBRICATING THE THROTTLE CABLE ................................................ 3-13
CLEANING THE AIR FILTER ELEMENT................................................. 3-14
CHECKING THE THROTTLE BODY JOINT ............................................ 3-15
CHECKING THE BREATHER HOSES .................................................... 3-15
CHECKING THE EXHAUST SYSTEM..................................................... 3-15
CHECKING THE FUEL LINE ................................................................... 3-16
CHECKING THE ENGINE OIL LEVEL..................................................... 3-16
CHANGING THE ENGINE OIL ................................................................ 3-17
ADJUSTING THE ENGINE IDLING SPEED ............................................ 3-18
ADJUSTING THE VALVE CLEARANCE ................................................. 3-19
CLEANING THE SPARK ARRESTER ..................................................... 3-23
CHASSIS........................................................................................................ 3-24
BLEEDING THE BRAKE SYSTEM .......................................................... 3-24
CHECKING THE BRAKE HOSE .............................................................. 3-25
ADJUSTING THE FRONT BRAKE .......................................................... 3-25
ADJUSTING THE REAR BRAKE ............................................................. 3-26
CHECKING THE FRONT BRAKE PADS ................................................. 3-26
CHECKING THE REAR BRAKE PADS ................................................... 3-28
CHECKING THE REAR BRAKE PAD INSULATOR ................................ 3-29
CHECKING THE BRAKE FLUID LEVEL.................................................. 3-29
ADJUSTING THE DRIVE CHAIN SLACK ................................................ 3-30
CHECKING THE FRONT FORK LEGS ................................................... 3-31
CHECKING THE FRONT FORK PROTECTOR GUIDE .......................... 3-31
CLEANING THE FRONT FORK OIL SEAL AND DUST SEAL ................ 3-31
AIR BLEEDING FROM FRONT FORK .................................................... 3-31
ADJUSTING THE FRONT FORK LEGS .................................................. 3-32
CHECKING THE SWINGARM OPERATION ........................................... 3-33
CHECKING THE REAR SUSPENSION ................................................... 3-33

PERIODIC MAINTENANCE
3-6
COOLING SYSTEM
Check coolant lev-
el and leakage
Check radiator cap
operation
Replace coolant Every two years
Inspect hoses
OUTSIDE NUTS
AND BOLTS
RetightenRefer to “STARTING AND
BREAK-IN” on page 1-32.
AIR FILTER
Clean and lubri-
cateUse foam air-filter oil or equiv-
alent oil.
Replace
OIL FILTER
Replace
ENGINE GUARD
Replace Breakage
FRAME
Clean and inspect
FUEL TANK, FUEL
PUMP
Clean and inspect
FUEL HOSE
Inspect
Replace Every four yearsITEMAfter
break-
inEvery
raceEvery
third
(or
500
km)Every
fifth
(or
1,000
km)As re-
quiredRemarks

PRE-OPERATION INSPECTION AND MAINTENANCE
3-9
EAS2GB2081
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EAS2GB2082GENERAL INSPECTION AND MAINTENANCE
TIP
Perform usual maintenance enough so that, in the race course, a confirmation of that and simple set-
ting adjustments may only be left, in order to get enough time to use effectively.ITEM inspect Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.3-10 – 12
FuelCheck that a fresh gasoline is filled in the fuel tank.
Check the fuel line for leakage.1-32
Engine oilCheck that the oil level is correct. Check the crank-
case and oil line for leakage.3-16 – 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and
that the clutch operates smoothly.3-12 – 13
Throttle grip/HousingCheck that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and
housing, if necessary.3-13 – 14
BrakesCheck the play of front brake and effect of front and
rear brake.3-24 – 30
Drive chainCheck drive chain slack and alignment. Check that
the drive chain is lubricated properly.3-30
5-68 – 69
WheelsCheck for excessive wear and tire pressure. Check
for loose spokes and have no excessive play.3-35 – 36
SteeringCheck that the handlebar can be turned smoothly and
have no excessive play.3-36 – 37
Front forks and rear
shock absorberCheck that they operate smoothly and there is no oil
leakage.3-31 – 35
Cables (wires)Check that the clutch and throttle cables move
smoothly. Check that they are not caught when the
handlebars are turned or when the front forks travel
up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and
has no cracks.3-15 – 16
Rear wheel sprocketCheck that the rear wheel sprocket tightening bolt is
not loose.5-10 – 11
LubricationCheck for smooth operation. Lubricate if necessary. 3-13
3-37 – 38
Bolts and nutsCheck the chassis and engine for loose bolts and
nuts.1-36 – 37
Lead connectorsCheck that the AC magneto, ECU and ignition coil are
connected tightly.1-11 – 14
SettingsIs the machine set suitably for the condition of the rac-
ing course and weather or by taking into account the
results of test runs before racing? Are inspection and
maintenance completely done?4-1 – 8

ENGINE
3-10
EAS2GB2083
ENGINE
EAS2GB2084CHECKING THE COOLANT LEVELEWA
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Stand the vehicle upright on a level surface.
2. Remove:
• Radiator cap “1”
3. Check:
• Coolant level
Maximum level “a” or below  Add coolant
up to the maximum level.
ECA
NOTICE
• Adding water instead of coolant lowers the
antifreeze content. If, therefore, water is
used instead of coolant, check, and if nec-
essary, adjust the antifreeze concentra-
tion.
• Use only distilled water. However, if dis-
tilled water is not available, soft water may
be used.
4. Start the engine, warm this up for 3 minutes,
and then stop it.
5. Check:
• Coolant level
TIP
Before checking the coolant level, wait a few
minutes until the coolant has settled.
EAS2GB2085CHECKING THE COOLING SYSTEM
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
• Air filter case cover
Refer to “THROTTLE BODY” on page 8-7.
2. Check:
• Radiator
• Radiator hoses
Crack/damage  Replace.
Refer to “RADIATOR” on page 7-1.
3. Install:
• Air filter case cover
Refer to “THROTTLE BODY” on page 8-7.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GB2086CHANGING THE COOLANTEWA
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Place a container under the engine.
2. Remove:
• Coolant drain bolt “1”
3. Remove:
• Radiator cap
Slowly loosen the radiator cap to drain cool-
ant.
TIP
When the radiator cap is loosened, coolant will
gush out transversely; therefore, bring the con-
tainer near to the outlet.
4. Thoroughly flush the cooling system with
clean tap water.
1. Radiator
1

ENGINE
3-11
5. Install:
• Copper washer
• Coolant drain bolt
6. Pour coolant.
EWA
WARNING
• If coolant splashes in your eyes, thorough-
ly wash them with water and consult a
doctor.
• If coolant splashes on your clothes, quick-
ly wash it away with water and then with
soap and water.
• If coolant is swallowed, induce vomiting
and get immediate medical attention.
ECA
NOTICE
• Adding water instead of coolant lowers the
antifreeze content of the coolant. If water
is used instead of coolant check, and if
necessary, correct the antifreeze concen-
tration of the coolant.
• Use only distilled water. However, if dis-
tilled water is not available, soft water may
be used.
• If coolant comes into contact with painted
surfaces, immediately wash them with wa-
ter.
• Do not mix different types of antifreeze.
7. Install:
• Radiator cap
8. Start the engine, warm this up for 3 minutes,
stop it, and then wait for it to cool down.
9. Check:
• Coolant level
Refer to “CHECKING THE COOLANT LEV-
EL” on page 3-10.
EAS2GB2087CHECKING THE RADIATOR CAP
1. Check:
• Seal (radiator cap) “1”
• Valve and valve seat “2”Crack/damage  Replace.
Exist fur deposits  Clean or replace.
EAS2GB2088CHECKING THE RADIATOR CAP OPENING
PRESSURE
1. Check:
• Radiator cap opening pressure
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Install the radiator cap tester adapter “2” and
the radiator cap tester “3” to the radiator cap
“1,” and activate the tester to check whether
it can stay for 5 to 10 seconds within stan-
dard pressure values.
TIP
Before attaching the cap to the tester, apply
water to its sealing surface.
No stay  Replace.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
Coolant drain bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended coolant
High quality ethylene glycol
anti-freeze containing anti-cor-
rosion for aluminum engine
Radiator capacity (including all
routes)
1.00 L (1.06 US qt, 0.88 Imp.qt)
Coolant mixing ratio
1:1 (Coolant:Water)
New
T R..
Radiator cap opening pressure
107.9–137.3 kPa (1.08–1.37 kg/
cm
2,15.6–19.9 psi)
Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984

ENGINE
3-12
EAS2GB2089CHECKING THE COOLANT CIRCULATORY
SYSTEM FOR LEAKS
1. Check:
• Coolant level
2. Install:
• Radiator cap tester “1”
• Adapter “2”
3. Activate the tester to apply the test pressure.
ECA
NOTICE
• Do not apply such a high pressure as ex-
ceeds the test pressure.
• Make sure that a checkup after the cylin-
der head gasket is replaced is made after 3
minutes of warm-up.
• Make sure that coolant is filled up to the
upper level beforehand.
4. Check:
• Pressure value
No stay for 5 to 10 seconds at the test pres-
sure value  Correct.
• Radiator
• Radiator hose connections
Coolant leaks  Correct or replace.
• Radiator hoses
Bulges  Replace
EWA
WARNING
When the radiator cap tester is removed,
coolant will spout; therefore, cover it with a
cloth beforehand.
EAS2GB2090ADJUSTING THE CLUTCH LEVER FREE
PLAY
1. Check:
• Clutch lever free play “a”
Out of specification  Regulate.
2. Adjust:
• Clutch lever free play
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
Handlebar side
a. Turn the adjuster “1” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained.
TIP
If the clutch lever free play cannot be obtained
on the handlebar side, use the adjuster on the
clutch cable side.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
Clutch cable side
a. Slide the clutch cable cover.
b. Loosen the locknut “1”. Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984
Test pressure value
196 kPa (1.96 kg/cm
2, 27.9 psi)
Clutch lever free play
7.0–12.0 mm (0.28–0.47 in)
Direction “a”
Clutch lever free play is increased.
Direction “b”
Clutch lever free play is decreased.
a b
1

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

CYLINDER HEAD
6-18
EAS2GB2246
CYLINDER HEAD
Removing the cylinder head
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.
Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 6-1.
Radiator hose Disconnect.
Coolant temperature sensor coupler Disconnect.
Throttle body Refer to “THROTTLE BODY” on page 8-7.
Camshaft Refer to “CAMSHAFT” on page 6-11.
Upper engine bracket Refer to “ENGINE REMOVAL” on page 6-1.
1 Nut (cylinder head) 2
2 Bolt (cylinder head) 4
3 Cylinder head 1
4 Cylinder head gasket 1
5 Timing chain guide (intake side) 1
6 Oil check bolt 1
6
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
33 Nm (3.3 m kgf, 24 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.