2014 YAMAHA YZ250F check engine

ENGINE
3-8
EAS1SM1069
ENGINE
EAS1SM1070CHECKING THE COOLANT LEVELEWA1DX1003
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.
ECA1DX1004
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 several
minutes, and then stop it.
5. Check:
• Coolant level
TIP
Before checking the coolant level, wait a few
minutes until the coolant has settled.
EAS1SM1071CHECKING THE COOLING SYSTEM
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-5.
2. Check:
•RADIATOR
• Radiator hoses
Crack/damage  Replace.
Refer to “RADIATOR” on page 6-1.
3. Install:
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-5.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
EAS1SM1072CHANGING THE COOLANTEWA1DX1004
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
3-9
5. Install:
• Copper washers
• Coolant drain bolt
6. Pour coolant.
EWA13040
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.
ECA13480
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.
• If coolant comes into contact with painted
surfaces, immediately wash them with wa-
ter.
• Do not mix different types of coolant.
7. Install:
• Radiator cap
8. Start the engine, warm this up for several
minutes, stop it, and then wait for it to cool
down.
9. Check:
• Coolant level
Refer to “CHECKING THE COOLANT LEV-
EL” on page 3-8.
EAS1SM1073CHECKING THE RADIATOR CAP
1. Check:
• Seal (radiator cap) “1”
• Valve and valve seat “2”Crack/damage  Replace.
Exist fur deposits  Clean or replace.
EAS1SM1074CHECKING THE RADIATOR CAP OPENING
PRESSURE
1. Check:
• Radiator cap opening pressure
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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.
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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
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Radiator cap opening pressure
108–137 kPa (1.08–1.37 kg/cm2,
15.7–19.9 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
3-10
EAS1SM1075CHECKING 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 2
to 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.
EAS1SM1076ADJUSTING THE CLUTCH LEVER POSI-
TION
1. Adjust:
• Clutch lever position “a”
Loosen the locknut “1” and use the adjuster
“2” to adjust the clutch lever position “a” as
desired.
2. Tighten:
• Locknut
EAS1SM1077ADJUSTING THE CLUTCH LEVER FREE
PLAY
1. Check:
• Clutch lever free play “a”
Out of specification  Regulate.
2. Adjust:
• Clutch lever free play
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Handlebar side
a. Turn the adjuster “1” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained. 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)
Locknut
4.8 Nm (0.48 m·kgf, 3.5 ft·lbf)
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.
1
2
a
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ENGINE
3-11
TIP
If the clutch lever free play cannot be obtained
on the handlebar side, use the adjuster on the
clutch cable side.
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Clutch cable side
a. Slide the clutch cable cover.
b. Loosen the locknut “1”.
c. Turn the adjuster “2” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained.
d. Tighten the locknut “1”.
e. Return the clutch cable cover to its original
position.
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EAS1SM1078ADJUSTING THE THROTTLE GRIP FREE
PLAY
TIP
Prior to adjusting throttle grip free play, the en-
gine idling speed should be adjusted.
1. Check:
• Throttle grip free play “a”
Out of specification  Regulate.
2. Adjust:
• Throttle grip free play
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a. Loosen the locknut “1”.
b. Turn the adjuster “2” until the specified free
play is obtained.
c. Tighten the locknut.
EWA33DD008
WARNING
After adjusting the throttle grip free play,
turn the handlebar to the right and to the left
to ensure that this does not cause the en-
gine idling speed to change.
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Direction “a”
Clutch lever free play is increased.
Direction “b”
Clutch lever free play is decreased.
Locknut
4.3 Nm (0.43 m·kgf, 3.1 ft·lbf)
a b
1
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1a
b
2
b
Throttle grip free play
3.0–5.0 mm (0.12–0.20 in)
Direction “a”
Throttle grip free play is increased.
Direction “b”
Throttle grip free play is decreased.
1 2
b
a

ENGINE
3-12
EAS1SM1079LUBRICATING THE THROTTLE CABLE
1. Remove:• Cover (throttle cable cap) “1”
• Cover (grip cap) “2”
• Throttle grip cap “3”
2. Lubricate: • Throttle cable end “a”
3. Install: • Throttle grip cap
• Screw (throttle grip cap)
4. Install: • Cover (grip cap)
• Cover (throttle cable cap)
EWA
WARNING
Check that the throttle grip moves smooth-
ly. If this does not move smoothly, correct
the installed positions.
EAS1SM1080CLEANING THE AIR FILTER ELEMENT
1. Remove:• Fuel tank cap cover “1”
Refer to “FUEL TANK CAP” on page 1-21.
• Air filter case cover “2” 2. Remove:
• Air filter mounting bolt “1”
• Air filter element “2”
• Air filter guide “3” (from the air filter element)
3. Wash: • Air filter element
EWA
WARNING
Do not use gasoline or organic (acid/alka-
line) volatile oil for washing.
TIP
After washing the element with air filter cleaner
or kerosene, squeeze and dry it completely.
ECA33DD016
NOTICE
Do not twist the element when squeezing
the element.
Recommended lubricant
Lithium-soap-based grease
Screw (throttle grip cap) 3.8 Nm (0.38 m·kgf, 2.8 ft·lbf)
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1
2
13
2

ENGINE
3-13
4. Check:
• Air filter element
Damage  Replace.
5. Foam-air-filter oil or equivalent oil to the ele-
ment
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”
• Air filter case cover mounting bolt
TIP
Align the air filter case cover groove “a” with the
air filter case edge “b”.
8. Install:
• Fuel tank cap cover
EAS1SM1081CHECKING THE THROTTLE BODY JOINT
1. Check:
• Throttle body joint “1”
Refer to “CHECKING THE THROTTLE
BODY JOINT” on page 7-8.
EAS1SM1082CHECKING THE BREATHER HOSES
1. Check:
• Breather hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.
ECA14920
NOTICE
Make sure that the breather hoses are rout-
ed correctly.
EAS1SM1083CHECKING 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 5-1.
• Exhaust gas
Leaks  Replace the gasket.
Refer to “ENGINE REMOVAL” on page 5-1.
3. Check:
• Tightening torques Oil application quantify
50 g
Air filter mounting bolt
2 Nm (0.2 m·kgf, 1.4 ft·lbf)
Air filter case cover mounting bolt
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
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31
2
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a
b 1
Exhaust pipe bolt 1 and nut “1”
20 Nm (2.0 m·kgf, 14 ft·lbf)
Exhaust pipe 1 and exhaust pipe
2 bolt “2”
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Exhaust pipe 2 and silencer bolt
“3”
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Silencer and silencer bracket bolt
“4”
30 Nm (3.0 m·kgf, 22 ft·lbf)
1
T R..

ENGINE
3-14
4. Install:
• Exhaust pipe protector
EAS1SM1084CHECKING THE FUEL LINE
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
2. Check:
• Fuel hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.3. Install:
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
EAS1SM1085CHECKING THE ENGINE OIL LEVEL
1. Stand the vehicle upright on a level surface.
2. Start the engine, warm this up for 2–3 min-
utes, and then stop the engine and wait
about 5 minute.
3. Check:
• Oil level
The engine oil level should be between the
minimum level mark “a” and maximum level
mark “b”.
Below the minimum level mark  Add the
recommended engine oil to the proper level.
ECA33DD018
NOTICE
• Since engine oil also lubricates the clutch,
the wrong oil types or additives could
cause clutch slippage. Therefore, do not
add any chemical additives.
• Do not allow foreign material to enter the
crankcase. Exhaust pipe protector screw
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
LOCTITE®
2
1
4
3
T R..
1
Recommended brand
YAMALUBE
Recommended engine oil type
SAE10W-30, SAE10W-40,
SAE10W-50, SAE15W-40,
SAE20W-40 or SAE20W-50
Recommended engine oil grade
API service SG type or higher,
JASO standard MA
a b

ENGINE
3-15
EAS1SM1086CHANGING THE ENGINE OIL
Stand the vehicle upright on a level surface.
1. Start the engine, warm this up for several
minutes, and then stop the engine and wait
about 5 minutes.
2. Place an oil pan under the drain bolt.
3. Remove:
• Oil filler cap “1”
• Drain bolt (with gasket) “2”
4. If the oil filter element is also to be replaced,
perform the following procedure.
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a. Remove the oil filter element cover “1” and
oil filter element “2”.
b. Replace the O-rings “3”.c. Install the new oil filter element and the oil fil-
ter element cover.
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5. To check the oil strainer, perform the follow-
ing procedure.
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a. Remove the oil strainer “1”.
b. Check the oil strainer.
Damage  Replace.
Clogging due to dirt  Wash with kerosene.
c. Replace the O-rings “2”.
d. Install the oil strainer.
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6. Install:
•Gaskets
• Drain bolt
1
2
Oil filter element cover bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil strainer bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Drain bolt
20 Nm (2.0 m·kgf, 14 ft·lbf)
1
3
2
New
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1
2New
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New
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