2014 YAMAHA YZ450F fuel cap

1
GENERAL INFORMATION
LOCATION OF IMPORTANT LABELS............................................................ 1-1
DESCRIPTION .................................................................................................. 1-4
IDENTIFICATION ............................................................................................. 1-5
VEHICLE IDENTIFICATION NUMBER ...................................................... 1-5
ENGINE SERIAL NUMBER ....................................................................... 1-5
MODEL LABEL........................................................................................... 1-5
FEATURES ....................................................................................................... 1-6
OUTLINE OF THE FI SYST EM .................................................................. 1-6
FI SYSTEM....................................... .......................................................... 1-7
INCLUDED PARTS .......................................................................................... 1-8
SIDESTAND ............................................................................................... 1-8
SPARK PLUG WRENCH ........................................................................... 1-8
NIPPLE WRENCH...................................................................................... 1-8
HANDLEBAR PROTECTOR .. .................................................................... 1-8
FUEL HOSE JOINT COVER ...................................................................... 1-8
COUPLER FOR CONNECTING OPTIONAL PART................................... 1-8
IMPORTANT INFORMATION ........................................................................ 1-10
PREPARATION FOR REMOVAL A ND DISASSEMBLY.......................... 1-10
REPLACEMENT PARTS.......................................................................... 1-10
GASKETS, OIL SEALS AND O-RINGS ................................................... 1-11
LOCK WASHERS/PLATES AND COTTER PINS .................................... 1-11
BEARINGS AND OIL SEALS ................................................................... 1-11
CIRCLIPS ................................................................................................. 1-11
BASIC SERVICE INFORMATION .................................................................. 1-12
ELECTRICAL SYSTEM.......... .................................................................. 1-12
SPECIAL TOOLS ........................................................................................... 1-15
CONTROL FUNCTIONS ................................................................................ 1-20
ENGINE STOP SWITCH .......................................................................... 1-20
CLUTCH LEVER ................................................................................... ... 1-20
SHIFT PEDAL .......................................................................................... 1-20
KICKSTARTER LEVER.......... .................................................................. 1-20
THROTTLE GRIP ..................................................................................... 1-20
FRONT BRAKE LEVER ........................................................................... 1-20
REAR BRAKE PEDAL.............................................................................. 1-21
STARTER KNOB/IDLE SCREW .............................................................. 1-21
FUEL TANK CAP ..................................................................................... 1-21

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

CONTROL FUNCTIONS
1-21
REAR BRAKE PEDAL
The rear brake pedal “1” is in the right of the
chassis. Press down on the brake pedal to ac-
tivate the rear brake.
EAS1SL1040STARTER KNOB/IDLE SCREW
Starting a cold engine requires a larger amount
of intake air, which is supplied by the starter
knob/idle screw “1.”
Pulling the knob toward “a” turns ON the start-
er, resulting in a larger amount of intake air.
Pushing the knob toward “b” turns OFF the
starter.
EWA@
WARNING
While handling the starter knob/idle screw,
take care not to burn yourself on exhaust
pipes.
EAS1SL1040FUEL TANK CAP
Fuel tank cap “1” is located under the fuel tank
cap cover “2”.
Remove the fuel tank cap cover to open the fuel
tank cap.
TIP
• To remove the fuel tank cap cover, insert fin-gers under part “a”, and then use both hands
to lift it up towards the rear of the vehicle.
• Install the fuel tank cap cover after placing the
bands “3” all the way in under the seat.
1
a b1
1
23
a
2

STARTING AND BREAK-IN
1-22
EAS1SL1041
STARTING AND BREAK-IN
EAS1SL1042FUEL
Always use the recommended fuel as stated
below. Also, be sure to use new gasoline the
day of a race.
JCA
NOTICE
Use only unleaded gasoline. The use of
leaded gasoline will cause severe damage
to the engine internal parts such as valves,
piston rings, and exhaust system, etc.
TIP
Your Yamaha engine has been designed to use
premium unleaded gasoline with a pump oc
-
tane number [(R+M)/2] of 91 or higher, or a re-
search octane number of 95 or higher. If
knocking (or pinging) occurs, use a gasoline of
a different brand.
JWA
WARNING
• For refueling, be sure to stop the engine
and use enough care not to spill any fuel.
Also be sure to avoid refueling close to a
fire.
• Refuel after the engine, exhaust pipe, etc.
have cooled off.
Gasohol (For USA and Canada)
There are two types of gasohol: gasohol con-
taining ethanol and that containing methanol.
Gasohol containing ethanol can be used if the
ethanol content does not exceed 10%. Gasohol
containing methanol is not recommended by
Yamaha because it can cause damage to the
fuel system or vehicle performance problems.
EAS1SL1043STARTING A COLD ENGINE
1. Press the shift pedal to neutral.
2. Pull the starter knob/idle screw “1” to its full
length.
TIP
When the ambient temperature is 15°C (59°F)
or below, use the starter knob/idle screw.
3. Push down the kickstarter lever lightly until
resistance is felt.
4. Fully close the throttle, and push down the
kickstarter lever in a stroke.
5. Immediately release the kickstarter lever.EWA
WARNING
Do not open the throttle at the moment
when you kick the kickstarter lever, be
-
cause this may kick back
TIP
If it fails to start, fully open the throttle grip and
give 10 to 20 slow kicks to clear the engine of
the rich air-fuel mixture retained in it.
6. When the engine starts running, warm this
up one or two minutes at a steady speed (of
3,000 to 5,000 r/min), and then return the
starter knob/idle screw to its original posi
-
tion.
EWA
WARNING
Since exhaust gas contains harmful ingre-
dients, do not start or warm it up at an ill-
ventilated place or a closed narrow place.
Recommended fuel
Premium unleaded gasoline
Fuel tank capacity
7.5 L (1.98 US gal, 1.7 lmp gal)
1

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
2-20
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