radiator cap YAMAHA YZ450F 2014 Owners Manual

DESCRIPTION
1-4
EAS1SL1009
DESCRIPTION
TIP
Designs and specifications of the vehicle are subject to change without notice. Therefore, please
note that the descriptions in this manual may be different from those for the vehicle you have pur
-
chased.
1. Clutch lever10. Coolant drain bolt
2. Front brake lever11. Rear brake pedal
3. Throttle grip12. Air filter
4. Radiator cap13. Drive chain
5. Fuel tank cap14. Shift pedal
6. Engine stop switch15. Oil level check window
7. Fuel tank16. Starter knob/idle screw
8. Kickstarter lever17. Front fork
9. Radiator
2 1
6
78 954 3
11 10 17 16 15 14 1312

SPECIAL TOOLS
1-16
Radiator cap tester
90890-01325
Mityvac cooling system tester
kit
YU-24460-A
This tool is used to check the
radiator and the radiator cap.
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984
This tool is used to check the
radiator and the radiator cap.
Steering nut wrench
90890-01403
Exhaust flange nut wrench
YU-A9472
This tool is used to remove or
tighten the steering nut.
Cap bolt wrench
90890-01500
YM-01500
This tool is used to remove or
tighten the base valve.
Cap bolt ring wrench
90890-01501
YM-01501
This tool is used to loosen or
tighten the damper assem
-
bly.
Fork seal driver
90890-01502
YM-A0948
This tool is used to install the
oil seal of the front fork.
Spoke nipple wrench (6–7)
90890-01521
YM-01521
This tool is used to tighten the
spoke.
Tool name/Part number How to use Illustration

ENGINE SPECIFICATIONS
2-2
EAS1SL1053
ENGINE SPECIFICATIONS
Engine
Engine type Liquid cooled 4-stroke, DOHC
Displacement 449 cm3
Cylinder arrangement Single cylinder
Bore  stroke 97.0  60.8 mm (3.82  2.39 in)
Compression ratio 12.50:1
Starting system Kickstarter
Fuel
Recommended fuel Premium unleaded gasoline only
Fuel tank capacity 7.5 L (1.98 US gal, 1.65 Imp.gal)
Engine oil
Lubrication system Wet sump
Recommended brand YAMALUBE
Type SAE 10W-30, SAE 10W-40, SAE 15W-40, 
SAE 20W-40 or SAE 20W-50
Recommended oil grade API service SG type or higher, 
JASO standard MA
Engine oil quantity
Quantity (disassembled) 0.95 L (1.00 US qt, 0.84 Imp.qt)
With oil filter element replacement 0.69 L (0.73 US qt, 0.61 Imp.qt)
Without oil filter element replacement 0.67 L (0.71 US qt, 0.59 Imp.qt)
Oil filter
Oil filter type Paper
Oil pump
Oil pump type Trochoid
Inner-rotor-to-outer-rotor-tip clearance Less than 0.150 mm (0.0059 in)
Limit 0.20 mm (0.0079 in)
Outer-rotor-to-oil-pump-housing clearance 0.13–0.18 mm (0.0051–0.0071 in)
Limit 0.24 mm (0.0094 in)
Oil-pump-housing-to-inner-and-outer-rotor 
clearance 0.06–0.11 mm (0.0024–0.0043 in)
Limit 0.17 mm (0.0067 in)
Cooling system
Radiator capacity (including all routes) 1.04 L (1.10 US qt, 0.92 Imp.qt)
Radiator capacity 0.57 L (0.60 US qt, 0.50 mp.qt)
Radiator cap opening pressure 108–137 kPa (1.08–1.37 kg/cm2 15.7–19.9 psi)
Radiator core
Width 112.6 mm (4.43 in)
Height 235.0 mm (9.25 in)
Depth 28.0 mm (1.10 in)
Water pump
Water pump type Single suction centrifugal pump
Spark plug
Manufacturer/model NGK/CR8E
Spark plug gap 0.7–0.8 mm (0.028–0.031 in)

TIGHTENING TORQUES
2-14
EAS1SL1057ENGINE TIGHTENING TORQUES
TIP
- marked portion shall be checked for torque tightening after break-in or before each race.
ITEMThread
sizeQ’tyTIGHTENING TORQUESRemarks
Camshaft cap boltM6810 Nm (1.0 m·kgf, 7.2 ft·lbf)
Cylinder head blind plugM12128 Nm (2.8 m·kgf, 20 ft·lbf)
Spark plugM10113 Nm (1.3 m·kgf, 9.4 ft·lbf)
Cylinder head stud bolt (exhaust
pipe)M637 Nm (0.7 m·kgf, 5.1 ft·lbf)
Cylinder head boltsM94See TIP.*1
Cylinder head boltsM6210 Nm (1.0 m·kgf, 7.2 ft·lbf)
Cylinder head cover boltM6310 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil passage plug (cylinder head)M8115 Nm (1.5 m·kgf, 11 ft·lbf)
Cylinder boltM6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil pressure check boltM6210 Nm (1.0 m·kgf, 7.2 ft·lbf)
Balancer weight plate screwM6310 Nm (1.0 m·kgf, 7.2 ft·lbf)
Balancer driven gear nutM14150 Nm (5.0 m·kgf, 36 ft·lbf)
Use a
lock
washer.
Balancer nutM10145 Nm (4.5 m·kgf, 33 ft·lbf)
Use a
lock
washer.
Timing chain guide stopper plate
(exhaust side)M6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Timing chain tensioner cap boltM616 Nm (0.6 m·kgf, 4.3 ft·lbf)
Timing chain tensioner boltM6210 Nm (1.0 m·kgf, 7.2 ft·lbf)
Coolant drain boltM6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Radiator hose clamp screwM681.5 Nm (0.15 m·kgf, 1.1 ft·lbf)
Radiator boltM6410 Nm (1.0 m·kgf, 7.2 ft·lbf)
Radiator pipe bolt M6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Radiator pipe joint bolt M6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Water pump housing cover boltM6410 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil pump boltM525 Nm (0.5 m·kgf, 3.6 ft·lbf)
Oil pump cover screwM412.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
Oil strainer boltM6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil passage cover bolt (left crank-
case)M6110 Nm (1.0 m·kgf, 7.2 ft·lbf)
Throttle cable cover boltM513.5 Nm (0.35 m·kgf, 2.5 ft·lbf)
Throttle body joint boltM6210 Nm (1.0 m·kgf, 7.2 ft·lbf)
Throttle body joint clamp boltM513.0 Nm (0.30 m·kgf, 2.2 ft·lbf)
Air filter joint clamp boltM413.5 Nm (0.35 m·kgf, 2.5 ft·lbf)
Air filter case boltM637 Nm (0.7 m·kgf, 5.1 ft·lbf)
LT
M
LT
LT
LT

TIGHTENING TORQUES
2-20
TIP
1. First, tighten the lower ring nut approximately 38 Nm (3.8 m·kgf, 27 ft·lbf) by using the steering nut
wrench, then loosen the lower ring nut one turn.
2. Retighten the lower ring nut 7 Nm (0.7 m·kgf, 5.1 ft·lbf).
Drive chain support nutM627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Drive chain guide boltM534.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
Rear frame and left cover boltM627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Fuel tank bolt (front side)M627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Fuel tank bolt (rear side)M619 Nm (0.9 m·kgf, 6.5 ft·lbf)
Fuel tank bracket bolt (front side)M647 Nm (0.7 m·kgf, 5.1 ft·lbf)
Fuel tank bracket bolt (rear side)M627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Fuel pump boltM564.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
Fuel inlet pipe screwM523.4 Nm (0.34 m·kgf, 2.5 ft·lbf)
Fuel tank cap cover boltM624.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
Seat set bracket and fuel tank screwM617 Nm (0.7 m·kgf, 5.1 ft·lbf)
Seat boltM8222 Nm (2.2 m·kgf, 16 ft·lbf)
Left side cover boltM617 Nm (0.7 m·kgf, 5.1 ft·lbf)
Right side cover boltM627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Frame and air scoop boltM627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Fuel tank and air scoop boltM627 Nm (0.7 m·kgf, 5.1 ft·lbf)
Radiator guard and air scoop boltM647 Nm (0.7 m·kgf, 5.1 ft·lbf)
Front fender boltM6410 Nm (1.0 m·kgf, 7.2 ft·lbf)
Rear fender bolt (front side)M637 Nm (0.7 m·kgf, 5.1 ft·lbf)
Rear fender bolt (rear side)M6216 Nm (1.6 m·kgf, 12 ft·lbf)
Mud flap screw—21.3 Nm (0.13 m·kgf, 0.94 ft·lbf)
Number plate boltM617 Nm (0.7 m·kgf, 5.1 ft·lbf)
ITEMThread
sizeQ’ty TIGHTENING TORQUES Remarks

CABLE ROUTING DIAGRAM
2-40
1. Main harness
2. Radiator3. Throttle position sensor lead
4. Joint coupler
5. Intake air temperature sensor lead6. Intake air pressure sensor lead
7. Frame
8. Fuel hose9. High tension cord
10. Spark plug cap
11. Cylinder head cover12. Sub-wire harness
13. Injector coupler
14. Injector lead15. Throttle body
16. Air filter case
17. ECU18. Sub-wire harness coupler
A. Fix the main harness by the plastic clamp, and in-sert the projection of the plastic clamp into the
hole in the sheet metal of the radiator.
B. Insert the projection of the main harness into the
hole in the frame.
C. To the sub-wire harness
D. Pass the high tension cord above the fuel hose.
E. ±10°F. Install the spark plug cap with this facing the right
of the vehicle.
G. Push the spark plug cap home, where there shall
be no gap between it and the cylinder head cover.
H. Pass the injector lead to the top of the vehicle be-yond the fuel hose.I. Insert the coupler of the sub-wire harness into the
rib of the air filter case.
J. Pass the sub-wire harness between the ECU and
the air filter case.

3
PERIODIC CHECKS AND ADJUSTMENTS
MAINTENANCE INTERVALS.......................................................................... 3-1
MAINTENANCE INTERVALS .................................................................... 3-1
PRE-OPERATION INSPECTION AND MAINTENANCE................................. 3-7
GENERAL INSPECTION AND MAINTENANCE........................................ 3-7
ENGINE............................................................................................................ 3-8
CHECKING THE COOLANT LEVEL .......................................................... 3-8
CHECKING THE COOLING SYSTEM ....................................................... 3-8
CHANGING THE COOLANT...................................................................... 3-8
CHECKING THE RADIATOR CAP ............................................................ 3-9
CHECKING THE RADIATOR CAP OPENING PRESSURE ...................... 3-9
CHECKING THE COOLANT CIRCULATORY SYSTEM FOR LEAKS .... 3-10
ADJUSTING THE CLUTCH LEVER POSITION ...................................... 3-10
ADJUSTING THE CLUTCH LEVER FREE PLAY .................................... 3-10
ADJUSTING THE THROTTLE GRIP FREE PLAY .................................. 3-11
LUBRICATING THE THROTTLE CABLE ................................................ 3-12
CLEANING THE AIR FILTER ELEMENT................................................. 3-12
CHECKING THE THROTTLE BODY JOINT ............................................ 3-13
CHECKING THE BREATHER HOSES .................................................... 3-13
CHECKING THE EXHAUST SYSTEM..................................................... 3-13
CHECKING THE FUEL LINE ................................................................... 3-14
CHECKING THE ENGINE OIL LEVEL..................................................... 3-14
CHANGING THE ENGINE OIL ................................................................ 3-15
ADJUSTING THE ENGINE IDLING SPEED ............................................ 3-16
ADJUSTING THE VALVE CLEARANCE ................................................. 3-17
CHASSIS........................................................................................................ 3-21
BLEEDING THE BRAKE SYSTEM .......................................................... 3-21
CHECKING THE BRAKE HOSE .............................................................. 3-22
ADJUSTING THE FRONT BRAKE .......................................................... 3-22
ADJUSTING THE REAR BRAKE ............................................................. 3-23
CHECKING THE FRONT BRAKE PADS ................................................. 3-23
CHECKING THE REAR BRAKE PADS ................................................... 3-25
CHECKING THE REAR BRAKE PAD INSULATOR ................................ 3-26
CHECKING THE BRAKE FLUID LEVEL.................................................. 3-26
ADJUSTING THE DRIVE CHAIN SLACK ................................................ 3-27
CHECKING THE FRONT FORK LEGS ................................................... 3-28
CHECKING THE FRONT FORK PROTECTOR GUIDE .......................... 3-28
CLEANING THE FRONT FORK OIL SEAL AND DUST SEAL ................ 3-28
AIR BLEEDING FROM FRONT FORK .................................................... 3-28
ADJUSTING THE FRONT FORK LEGS .................................................. 3-29
CHECKING THE SWINGARM OPERATION ........................................... 3-30
CHECKING THE REAR SUSPENSION ................................................... 3-30
ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLY ................... 3-30
CHECKING THE TIRES ........................................................................... 3-32
CHECKING AND TIGHTENING THE SPOKES ....................................... 3-32
CHECKING THE WHEELS ...................................................................... 3-33

MAINTENANCE INTERVALS
3-3
NUT (ROTOR)
RetightenCheck for tightening torques.
EXHAUST PIPE, SI-
LENCER, PROTEC-
TOR
Inspect and re-
tighten
Check for exhaust leaks, and
tightening torques.
Clean
Replace fiver*
* When the exhaust sound be-
comes louder or when a per-
formance drop is felt.
CRANKSHAFT
Inspect and clean
THROTTLE BODY
Inspect
AIR FILTER
Clean and lubri-
cate
Use foam air-filter oil or equiv-
alent oil.
Replace
SPARK PLUG
Inspect and cleanCheck the electrodes and the
terminals for wear.
Replace
COOLING SYSTEM
Check coolant lev-
el and leakage
Check radiator cap
operationUse the radiator cap tester for
a checkup.
Check radiator cap
attached
Change the cool-
ant
Every two years
Inspect hoses
ENGINE GUARD
ReplaceBreakage
FRAME
Clean and inspect
ITEMAfter
break-
inEvery
race
(about
2.5
hours)Every
third
(about
7.5
hours)Every
fifth
(about
12.5
hours)As re-
quiredRemarks

PRE-OPERATION INSPECTION AND MAINTENANCE
3-7
EAS1SL1067
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.
EAS1SL1068GENERAL 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.
ITEMinspectPage
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.3-8 – 10
FuelCheck that a fresh gasoline is filled in the fuel tank.
Check the fuel line for leakage.1-22
Engine oilCheck that the oil level is correct. Check the crank-
case and oil line for leakage.3-14 – 16
Gear shifter and clutchCheck that gears can be shifted correctly in order and
that the clutch operates smoothly.3-10 – 11
Throttle grip/Housing
Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and
housing, if necessary.
3-11 – 12
BrakesCheck the play of front brake and effect of front and
rear brake.3-21 – 27
Drive chainCheck drive chain slack and alignment. Check that
the drive chain is lubricated properly.3-27
4-64 – 65
WheelsCheck for excessive wear and tire pressure. Check
for loose spokes and have no excessive play.3-32 – 33
SteeringCheck that the handlebar can be turned smoothly and
have no excessive play.3-33 – 34
Front forks and rear
shock absorberCheck that they operate smoothly and there is no oil
leakage.3-28 – 32
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.3-13 – 14
Rear wheel sprocketCheck that the rear wheel sprocket tightening bolt is
not loose.4-8 – 9
LubricationCheck for smooth operation. Lubricate if necessary. 3-12 , 3-34
Bolts and nutsCheck the chassis and engine for loose bolts and
nuts.1-25 – 26
Lead connectorsCheck that the AC magneto, ECU and ignition coil are
connected tightly.1-12 – 14
Settings
Is 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?10-1 – 8

ENGINE
3-8
EAS1SL1069
ENGINE
EAS1SL1070CHECKING 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.
EAS1SL1071CHECKING 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.
EAS1SL1072CHANGING 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