2015 YAMAHA YZ450F torque

EAS1SL5007
SYMBOLS
The following symbols are used in this manual for easier understanding.
TIP
The following symbols are not relevant to every vehicle.
SYMBOL DEFINITION SYMBOL DEFINITION
Serviceable with engine mounted Gear oil
Filling fluid Molybdenum disulfide oil
Lubricant Brake fluid
Special tool Wheel bearing grease
Tightening torque Lithium-soap-based grease
Wear limit, clearance Molybdenum disulfide grease
Engine speed Silicone grease
Electrical data Locking agent (LOCTITE®)
Engine oil Replace the part with a new one.
G
M
BF
B
T R..
LS
M
S
LT
E
New

STARTING AND BREAK-IN.......................................................................... 1-22
FUEL ........................................................................................................ 1-22
STARTING A COLD ENGINE .................................................................. 1-22
STARTING A WARM ENGINE ................................................................. 1-23
BREAK-IN PROCEDURES ...................................................................... 1-23
MAINTENANCE AFTER BREAK-IN.............................................................. 1-24
MAJOR MAINTENANCE .......................................................................... 1-24
TORQUE-CHECK POINTS............................................................................ 1-25
CLEANING AND STORAGE.......................................................................... 1-27
CLEANING ............................................................................................... 1-27
STORAGE ................................................................................................ 1-27

STARTING AND BREAK-IN
1-23
7. To stop the engine, push the engine stop
switch “1”.
TIP
Continue pushing the engine stop switch till the
engine comes to a full stop.
EAS1SL5045STARTING A WARM ENGINE
When the engine is warm, give a kick with the
throttle closed without using the starter knob/
idle screw.
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.
EAS1SL5046BREAK-IN PROCEDURES
A break-in is important so that rotating portion,
sliding surfaces, and mounted areas may fit
one another, and that the rider may become ac-
customed to the machine.
ECA
NOTICE
Before running, do maintenance on the air
filter element.
Refer to “CLEANING THE AIR FILTER ELE-
MENT” on page 3-12.
1. After warming up the engine, drive it for
about 20 minutes at a throttle opening of 1/2
or less.
2. Make a pit stop, and check mounted areas
for looseness, oil leaks, or other problems.
3. Then, drive it for about 40 minutes at a throt-
tle opening of 3/4 or less.
4. Make a pit stop again, and thoroughly check
mounted areas for looseness, oil leaks, or
other problems. Thorough checks and ad-
justments are required in particular for
stretch of cables, free play of the brake,
stretch of the drive chain, looseness of the
spoke, and so on.
ECA
NOTICE
After a break-in or after each race, always
check the points shown in “TORQUE-
CHECK POINTS” for tightening torques and
retighten them. (Refer to “TORQUE-CHECK
POINTS” on page 1-25.)
Also when the following parts are replaced,
a break-in is required.
• Cylinder and Crankshaft: A break-in is re-
quired for about an hour.
• Piston, Piston ring, Valve, Camshaft, and
Gear: A break-in is required for about 30
minutes at a throttle opening of 1/2 or less.
Observe the condition of the engine careful-
ly during a break-in.
For checkpoints for a break-in, see “MAIN-
TENANCE AFTER BREAK-IN”. If any prob-
lem is found, immediately stop the engine
and make a checkup.

MAINTENANCE AFTER BREAK-IN
1-24
EAS1SL5047
MAINTENANCE AFTER BREAK-IN
After a break-in, perform careful maintenance
to get ready for the next practice or race.
Refer to “PRE-OPERATION INSPECTION
AND MAINTENANCE” on page 3-7.
EAS1SL5048MAJOR MAINTENANCE
1. For the engine
• Leaks around the engine
Check for pressure leaks from the cylinder
head or the cylinder, oil leaks from the
crankcase or the case cover, leaks from the
coolant system, and other leaks.
• Check that the valve, the cylinder head, the
cylinder, the piston, and the piston ring fit
one another, and that contact between the
valve and the cylinder head, and that be-
tween the cylinder and the piston are cor-
rect.
• Engine oil change
Drain the oil, and check for dirt and foreign
materials such as metal chips. (If any foreign
material is mixed, disassemble and check
the crankcase.)
Pour the specified amount of the recom-
mended oil.
• AC magneto
Check for looseness in mounted areas of
the rotor and the stator.
Check that the connector is not being dis-
connected.
• Silencer
Check the main body and stay for cracks.
Check for leaks.
• Mounting bolts and nuts
Check for looseness in mounted areas of
parts, as well as engine mounting bolts and
engine brackets.
2. For the chassis
• Check welds and mounted areas of the
frame, the swingarm, the link, the bracket,
and so on, for looseness and cracks.
• Wheel (s)
Check the wheel for runout. Check the
spoke for looseness.
• Brake(s)
Check the brake disc mounting bolt for
looseness.
Check that the reservoir contains the speci-
fied amount of brake fluid. Check for leaks.• Cable
Grease and adjust cables.
•Drive chain
Lubricate the drive chain and adjust its ten-
sion.
• Fuel tank
Clean the inside of the fuel tank. Check for
leaks.
• Suspension
Check for oil leaks in the front fork or the rear
shock absorber. Check that the mounted
conditions are good.
• Sprocket
Check for looseness in the sprocket mount-
ed on the rear wheel.
• Mounting bolts and nuts
Check mounted areas for looseness.
JCA1SL1001
NOTICE
After a break-in or before each race, always
check the points shown in “TORQUE-
CHECK POINTS” for tightening torques and
retighten them. (Refer to “TORQUE-CHECK
POINTS” on page 1-25.)
• Greasing and oiling
Always grease or oil the specified points.

TORQUE-CHECK POINTS
1-25
EAS1SL5049
TORQUE-CHECK POINTS
Frame construction Frame to rear frame
Frame to engine protector
Combined seat and fuel tank Fuel tank to frame
Engine mounting Frame to engine
Engine bracket to engine
Engine bracket to frame
Seat Seat to frame
Steering Steering stem to handlebar Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Suspension Front Steering stem to front fork Front fork to upper bracket
Front fork to lower bracket
Rear Link Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Mounting of rear shock absorber Rear shock absorber and frame
Mounting of swingarm Tightening of pivot shaft
Wheel (s) Mounting of wheel Front Tightening of wheel axle
Tightening of axle holder
Tightening of spoke nipple
Rear Tightening of wheel axle
Wheel to rear wheel sprocket
Tightening of spoke nipple
Brake(s) Front Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handle-
bar
Tightening of bleed screw
Tightening of brake hose holder
Rear Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Tightening of brake hose holder
Fuel system Fuel pump to fuel tank
Plastic cover Tightening of number plate

TORQUE-CHECK POINTS
1-26
TIP
Concerning the tightening torque, refer to “TIGHTENING TORQUES” on page 2-13.Tightening of front fender
Tightening of fork leg protector
Tightening of air scoop
Left cover to rear frame
Tightening of side cover
Tightening of rear fender
Tightening of mud flap
Tightening of rear brake disc cov-
er
Tightening of rear brake caliper
cover

2
SPECIFICATIONS
GENERAL SPECIFICATIONS......................................................................... 2-1
ENGINE SPECIFICATIONS............................................................................. 2-2
CHASSIS SPECIFICATIONS........................................................................... 2-8
ELECTRICAL SPECIFICATIONS.................................................................. 2-12
TIGHTENING TORQUES............................................................................... 2-13
GENERAL TIGHTENING TORQUE SPECIFICATIONS .......................... 2-13
ENGINE TIGHTENING TORQUES .......................................................... 2-14
CHASSIS TIGHTENING TORQUES ........................................................ 2-18
LUBRICATION POINTS AND LUBRICANT TYPES..................................... 2-21
ENGINE .................................................................................................... 2-21
CHASSIS .................................................................................................. 2-23
LUBRICATION SYSTEM CHART AND DIAGRAMS..................................... 2-25
LUBRICATION DIAGRAMS ..................................................................... 2-25
CABLE ROUTING DIAGRAM........................................................................ 2-33

TIGHTENING TORQUES
2-13
EAS20320
TIGHTENING TORQUES
EAS1SL5057GENERAL TIGHTENING TORQUE SPECIFI-
CATIONS
This chart specifies tightening torques for stan-
dard fasteners with a standard ISO thread
pitch. Tightening torque specifications for spe-
cial components or assemblies are provided for
each chapter of this manual. To avoid warpage,
tighten multi-fastener assemblies in a criss-
cross pattern and progressive stages until the
specified tightening torque is reached. Unless
otherwise specified, tightening torque specifi-
cations require clean, dry threads. Compo-
nents should be at room temperature.
A. Distance between flats
B. Outside thread diameter
A (nut)B
(bolt)General tightening
torques
Nm m·kgf ft·lbf
10 mm 6 mm 6 0.6 4.3
12 mm 8 mm 15 1.5 11
14 mm 10 mm 30 3.0 22
17 mm 12 mm 55 5.5 40
19 mm 14 mm 85 8.5 61
22 mm 16 mm 130 13.0 94