2013 YAMAHA YZ450F fuel cap

FOREWORD
INTRODUCTION
Congratulations on your purchase of
a Yamaha YZ series. This model is
the culmination of Yamaha's vast ex-
perience in the production of paceset-
ting racing machines. It represents
the highest grade of craftsmanship
and reliability that have made Yama-
ha a leader.
This manual explains operation, in-
spection, basic maintenance and tun-
ing of your machine. If you have any
questions about this manual or your
machine, please contact your Yama-
ha dealer.
Yamaha continually seeks advance-
ments in product design and quality.
Therefore, while this manual contains
the most current product information
available at the time of printing, there
may be minor discrepancies between
your machine and this manual. If you
have any questions concerning this
manual, please consult your Yamaha
dealer.
PLEASE READ THIS MANUAL
CAREFULLY AND COMPLETELY
BEFORE OPERATING THIS MA-
CHINE. DO NOT ATTEMPT TO OP-
ERATE THIS MACHINE UNTIL YOU
HAVE ATTAINED A SATISFACTO-
RY KNOWLEDGE OF ITS CON-
TROLS AND OPERATING
FEATURES AND UNTIL YOU HAVE
BEEN TRAINED IN SAFE AND
PROPER RIDING TECHNIQUES.
REGULAR INSPECTIONS AND
CAREFUL MAINTENANCE,
ALONG WITH GOOD RIDING
SKILLS, WILL ENSURE THAT YOU
SAFETY ENJOY THE CAPABILI-
TIES AND THE RELIABILITY OF
THIS MACHINE.
IMPORTANT MANUAL
INFORMATION
Particularly important information is
distinguished in this manual by the
following notations.
This is the safety alert symbol. It is
used to alert you to potential per-
sonal injury hazards. Obey all safe-
ty messages that follow this
symbol to avoid possible injury or
death.
A WARNING indicates a hazardous
situation which, if not avoided,
could result in death or serious in-
jury.
A NOTICE indicates special pre-
cautions that must be taken to
avoid damage to the vehicle or oth-
er property.
A TIP provides key information to
make procedures easier or clearer.
SAFETY INFORMATION
THIS MACHINE IS DESIGNED
STRICTLY FOR COMPETITION
USE, ONLY ON A CLOSED
COURSE. It is illegal for this machine
to be operated on any public street,
road, or highway. Off-road use on
public lands may also be illegal.
Please check local regulations before
riding.
• THIS MACHINE IS TO BE OPER-
ATED BY AN EXPERIENCED RID-
ER ONLY.
Do not attempt to operate this ma-
chine at maximum power until you
are totally familiar with its character-
istics.
• THIS MACHINE IS DESIGNED TO
BE RIDDEN BY THE OPERATOR
ONLY.
Do not carry passengers on this
machine.
• ALWAYS WEAR PROTECTIVE
APPAREL.
When operating this machine, al-
ways wear an approved helmet with
goggles or a face shield. Also wear
heavy boots, gloves, and protective
clothing. Always wear proper fitting
clothing that will not be caught in
any of the moving parts or controls
of the machine.• ALWAYS MAINTAIN YOUR MA-
CHINE IN PROPER WORKING
ORDER.
For safety and reliability, the ma-
chine must be properly maintained.
Always perform the pre-operation
checks indicated in this manual.
Correcting a mechanical problem
before you ride may prevent an ac-
cident.
• GASOLINE IS HIGHLY FLAMMA-
BLE.
Always turn off the engine while re-
fueling. Take care to not spill any
gasoline on the engine or exhaust
system. Never refuel in the vicinity
of an open flame, or while smoking.
• GASOLINE CAN CAUSE INJURY.
If you should swallow some gaso-
line, inhale excess gasoline vapors,
or allow any gasoline to get into
your eyes, contact a doctor immedi-
ately. If any gasoline spills onto
your skin or clothing, immediately
wash skin areas with soap and wa-
ter, and change your clothes.
• ONLY OPERATE THE MACHINE
IN AN AREA WITH ADEQUATE
VENTILATION.
Never start the engine or let it run
for any length of time in an enclosed
area. Exhaust fumes are poison-
ous. These fumes contain carbon
monoxide, which by itself is odor-
less and colorless. Carbon monox-
ide is a dangerous gas which can
cause unconsciousness or can be
lethal.
• PARK THE MACHINE CAREFUL-
LY; TURN OFF THE ENGINE.
Always turn off the engine if you are
going to leave the machine. Do not
park the machine on a slope or soft
ground as it may fall over.
• THE ENGINE, EXHAUST PIPE,
MUFFLER, AND OIL TANK WILL
BE VERY HOT AFTER THE EN-
GINE HAS BEEN RUN.
Be careful not to touch them or to
allow any clothing item to contact
them during inspection or repair.
• PROPERLY SECURE THE MA-
CHINE BEFORE TRANSPORTING
IT.
For safety, drain the gasoline from
the fuel tank before transporting the
vehicle.

1-5
DESCRIPTION
DESCRIPTION
• The machine you have purchased may differ slightly from those shown in the following.
• Designs and specifications are subject to change without notice.
1. Clutch lever
2. Front brake lever
3. Throttle grip
4. Radiator cap
5. Fuel tank cap
6. Engine stop switch
7. Kickstarter crank
8. Fuel tank
9. Radiator10. Coolant drain bolt
11. Rear brake pedal
12. Valve joint
13. Air cleaner
14. Drive chain
15. Shift pedal
16. Oil level check window
17. Starter knob/idle screw
18. Front fork

1-13
SPECIAL TOOLS
Cap bolt wrench
YM-01500, 90890-01500This tool is used to loosen or tighten
the base valve.
Cap bolt ring wrench
YM-01501, 90890-01501This tool is used to loosen or tighten
the damper assembly.
Fork seal driver
YM-A0948, 90890-01502 This tool is used when install the fork
oil seal.
Spoke nipple wrench
YM-01521, 90890-01521 This tool is used to tighten the
spoke.
Pocket tester
YU-03112-C, 90890-03112 Use this tool to inspect the coil resis-
tance, output voltage and amper-
age.
Timing light
YM-33277-A, 90890-03141 This tool is necessary for checking
ignition timing.
Pressure gauge
YU-03153, 90890-03153 This tool is used to measure the fuel
pressure. Tool name/Part number How to use Illustration

2-2
GENERAL SPECIFICATIONS
Fuel:
Type Premium unleaded gasoline only
Tank capacity 6.2 L (1.40 Imp gal, 1.64 US gal)
Throttle body:
Type 30RA
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK (resistance type)
Gap 0.7–0.8 mm (0.028–0.031 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 2.652 (61/23)
Final drive Chain
Secondary reduction ratio 3.692 (48/13) (For USA, CDN)
3.769 (49/13) (For EUROPE, AUS, NZ, ZA)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio:
1st 1.929 (27/14)
2nd 1.533 (23/15)
3rd 1.278 (23/18)
4th 1.091 (24/22)
5th 0.952 (20/21)
Chassis: USA, CDN EUROPE AUS, NZ, ZA
Frame type Semi double cra-
dle←←
Caster angle 26.95° 26.80° 27.00°
Trail 118 mm (4.65 in) 117 mm (4.61 in) 120 mm (4.72 in)
Tire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 120/80-19 63M (For USA, CDN, AUS, NZ, ZA)
110/90-19 62M (For EUROPE)
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm
2, 15 psi)
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper

2-8
MAINTENANCE SPECIFICATIONS
Throttle position sensor:----
Throttle position sensor maximum resistance 5 kΩ----
Throttle position sensor variable resistance 0–2 kΩ (full closed) ----
Throttle position sensor input voltage 4–6 V ----
Fuel injection sensor:----
Crankshaft position sensor resistance 248–372 Ω----
Intake air pressure sensor output voltage 3.57–3.71 V at 101.3kPa (1.013 kg/cm
2,
14.41 psi)----
Atmospheric pressure sensor output voltage 3.57–3.71 V at 101.3kPa (1.013 kg/cm
2,
14.41 psi)----
Intake air temperature sensor 5.4–6.6 kΩat 0 °C (32 °F)
290–390 Ωat 80 °C (176 °F)----
Idling condition:----
Engine idle speed 1,900–2,100 r/min ----
Oil temperature 55–65 °C (131–149 °F) ----
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 in)
Bypass valve setting pressure 40–80 kPa (0.4–0.8 kg/cm
2, 5.69–11.38
psi)----
Cooling:
Radiator core size
Width 121.4 mm (4.78 in) ----
Height 235 mm (9.25 in) ----
Thickness 28 mm (1.10 in) ----
Radiator cap opening pressure 108–137 kPa (1.08–1.37 kg/cm
2, 15.4–
19.5 psi)----
Radiator capacity (total) 0.62 L (0.55 Imp qt, 0.66 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

2-14
TIGHTENING TORQUES
△Brake pedal mounting M8 1 26 Nm (2.6 m•kg, 19 ft•lb)
Brake pedal position locknut M6 1 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Rear brake master cylinder and frame M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Rear brake master cylinder cap M4 2 2 Nm (0.2 m•kg, 1.4 ft•lb)
△Rear brake hose union bolt (brake cali-
per)M10 1 30 Nm (3.0 m•kg, 22 ft•lb)Copper
washer
△Rear brake hose union bolt (brake master
cylinder)M10 1 30 Nm (3.0 m•kg, 22 ft•lb)Copper
washer
△Rear wheel axle and axle nut M22 1 135 Nm (13.5 m•kg, 98 ft•lb)
△Driven sprocket and wheel hub M8 6 42 Nm (4.2 m•kg, 30 ft•lb)
△Nipple (spoke) — 72 3 Nm (0.3 m•kg, 2.2 ft•lb)
△Disc cover and rear brake caliper M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Protector and rear brake caliper M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Drive chain puller adjust bolt and locknut M8 2 21 Nm (2.1 m•kg, 15 ft•lb)
Engine mounting:
△Upper engine bracket and frame M8 4 45 Nm (4.5 m•kg, 32 ft•lb)
△Front engine bracket and frame M8 4 34 Nm (3.4 m•kg, 24 ft•lb)
△Engine and engine bracket (front) M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Engine and engine bracket (upper) M10 2 45 Nm (4.5 m•kg, 32 ft•lb)
△Engine and frame (lower) M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Engine guard M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Lower engine guard M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Pivot shaft and nut M16 1 85 Nm (8.5 m•kg, 61 ft•lb)
△Relay arm and swingarm M14 1 70 Nm (7 m•kg, 50 ft•lb)
△Relay arm and connecting rod M14 1 80 Nm (8.0 m•kg, 58 ft•lb)
△Connecting rod and frame M14 1 80 Nm (8.0 m•kg, 58 ft•lb)
△Rear shock absorber and frame M10 1 56 Nm (5.6 m•kg, 40 ft•lb)
△Rear shock absorber and relay arm M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Rear shock absorber locknut M60 1 30 Nm (3.0 m•kg, 22 ft•lb)
△Rear frame and frame (upper) M8 1 32 Nm (3.2 m•kg, 23 ft•lb)
△Rear frame and frame (lower) M8 2 32 Nm (3.2 m•kg, 23 ft•lb)
△Swingarm and brake hose holder M5 4 3 Nm (0.3 m•kg, 2.2 ft•lb)
Upper drive chain tensioner M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Lower drive chain tensioner M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Drive chain support and swingarm M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Seal guard and swingarm M5 3 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Fuel tank (front) M6 2 9 Nm (0.9 m•kg, 6.5 ft•lb)
Fuel tank bracket (front) M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Fuel tank (rear) M6 2 9 Nm (0.9 m•kg, 6.5 ft•lb)
Fuel tank bracket (rear) M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Fuel pump M5 6 4 Nm (0.4 m•kg, 2.9 ft•lb)
Protector and fuel pump bracket M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Fuel tank side cover M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
Fuel tank and seat set bracket M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)Item
Thread
sizeQ'ty Tightening torque Remarks

3-5
PRE-OPERATION INSPECTION AND MAINTENANCE
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.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap. Check the cool-
ing system for leakage.P.3-6 – 7
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the fuel
line for leakage.P.1-17
Engine oilCheck that the oil level is correct. Check the crankcase and oil line
for leakage.P.3-9 – 10
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-7
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-8
Brakes Check the play of front brake and effect of front and rear brake. P.3-14 – 17
Drive chainCheck drive chain slack and alignment. Check that the drive chain
is lubricated properly.P.3-17 –18
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-21
SteeringCheck that the handlebar can be turned smoothly and have no ex-
cessive play.P.3-21 – 22
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage.
P.3-18 – 20
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 pipe Check that the exhaust pipe is tightly mounted and has no cracks. P.4-3 – 4
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-17
Lubrication Check for smooth operation. Lubricate if necessary. P.3-23
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-19
Lead connectorsCheck that the AC magneto, ECU and ignition coil are connected
tightly.P.1-10 – 11
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs be-
fore racing? Are inspection and maintenance completely done?P.8-1 – 5

3-8
ENGINE
ADJUSTING THE THROTTLE GRIP
FREE PLAY
1. Check:
• Throttle grip free play "a"
Out of specification→Adjust.
2. Adjust:
• Throttle grip free play
Adjustment steps:
a. Slide the adjuster cover.
b. Loosen the locknut "1".
c. Turn the adjuster "2" until the
specified free play is obtained.
d. Tighten the locknut.
Prior to adjusting throttle grip free
play, the engine idling speed should
be adjusted.
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 engine
idling speed to change.
LUBRICATING THE THROTTLE
1. Remove:
• Cover (throttle cable cap) "1"
• Cover (grip cap) "2"
• Throttle grip cap "3"2. Apply:
• Lithium soap base grease
On the throttle cable end "a".
3. Install:
• Throttle grip cap
• Screw (throttle grip cap)
• Cover (grip cap)
• Cover (throttle cable cap)
CHECKING THE THROTTLE
VALVE PULLY COVER DRAIN
HOSE
Drain the water that stays in the throt-
tle valve pulley cover after a machine
wash or a rainy weather ride.
1. Drain the water by picking up the
flat portion of the lower end "a" of
the drain hose.
CLEANING THE AIR FILTER
ELEMENT
1. Remove:
•Seat
2. Remove the fuel tank bolt (front)
"1" and lift the fuel tank.
Hold the fuel tank in position by the
use of the fuel tank holding cable "2".
3. Remove:
• Mounting bolt for air filter case
cover4. Loosen and release the binder "1"
and lift the air filter case lid.
Hold the air filter case lid by the use of
the binder.
5. Remove:
• Air filter guide
• Air filter element "1"
Do not remove the thin sheet (air
filter element 2) “2” under the air
filter element unless it is dirty. It is
there to prevent foreign matter
from dropping into the throttle
body. If the thin sheet must be re-
moved for cleaning, lift it carefully
to avoid loosening the dirt, and
then temporarily block the throttle
body opening with a clean, lint-free
cloth.
6. Clean:
• Air filter element
Clean them with solvent.
After cleaning, remove the remaining
solvent by squeezing the element.
• Do not twist the element when
squeezing the element.
• Leaving too much of solvent in
the element may result in poor
starting.
7. Inspect:
• Air filter element
Damage → Replace. Throttle grip free play
"a":
3–5 mm (0.12–0.20 in)
Screw (throttle grip cap):
4 Nm (0.4 m•kg, 2.9
ft•lb)