brake YAMAHA YZ450F 2016 User Guide

TIGHTENING TORQUES
2-18
Front wheel axle pinch bolt M8 4 21 Nm (2.1 m·kgf, 15 ft·lbf)
Front brake disc bolt M6 6 12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Rear brake disc bolt M6 6 14 Nm (1.4 m·kgf, 10 ft·lbf)
Footrest bracket bolt M10 4 55 Nm (5.5 m·kgf, 40 ft·lbf)
Rear brake pedal bolt M8 1 26 Nm (2.6 m·kgf, 19 ft·lbf)
Rear brake pedal position locknut M6 1 6 Nm (0.6 m·kgf, 4.3 ft·lbf)
Rear brake master cylinder bolt M6 2 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Rear brake master cylinder reservoir
cap boltM4 2 1.5 Nm (0.15 m·kgf, 1.1 ft·lbf)
Rear brake hose union bolt M10 2 30 Nm (3.0 m·kgf, 22 ft·lbf)
Rear brake caliper bleed screw M8 1 6 Nm (0.6 m·kgf, 4.3 ft·lbf)
Rear brake pad pin M10 1 17 Nm (1.7 m·kgf, 12 ft·lbf)
Rear brake pad pin plug M10 1 2.5 Nm (0.25 m·kgf, 1.8 ft·lbf)
Rear wheel axle nut M22 1 135 Nm (13.5 m·kgf, 98 ft·lbf)
Drive chain puller adjust bolt and
locknutM8 2 21 Nm (2.1 m·kgf, 15 ft·lbf)
Rear wheel sprocket nut M8 6 42 Nm (4.2 m·kgf, 30 ft·lbf)
Nipple (spoke) — 72 2.5 Nm (0.25 m·kgf, 1.8 ft·lbf)
Rear brake disc cover bolt M6 2 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Rear brake caliper protector bolt M6 2 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
Engine mounting bolt (upper side)M10 2 45 Nm (4.5 m·kgf, 33 ft·lbf)
Engine mounting bolt (front side) M10 1 55 Nm (5.5 m·kgf, 40 ft·lbf)
Engine mounting bolt (lower side) M10 1 53 Nm (5.3 m·kgf, 38 ft·lbf)
Engine bracket bolt (upper side) M8 4 36 Nm (3.6 m·kgf, 26 ft·lbf)
Engine bracket bolt (front side) M8 4 34 Nm (3.4 m·kgf, 25 ft·lbf)
Rear frame and frame bolt M8 4 38 Nm (3.8 m·kgf, 27 ft·lbf)
Engine guard bolt (right side) M6 1 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
Pivot shaft and nut M16 1 85 Nm (8.5 m·kgf, 61 ft·lbf)
Rear shock absorber assembly up-
per boltM10 1 56 Nm (5.6 m·kgf, 41 ft·lbf)
Rear shock absorber assembly low-
er boltM10 1 53 Nm (5.3 m·kgf, 38 ft·lbf)
Rear shock absorber locknut M60 1 30 Nm (3.0 m·kgf, 22 ft·lbf)
Relay arm bolt (swingarm side) M14 1 70 Nm (7.0 m·kgf, 51 ft·lbf)
Connecting arm bolt (relay arm side) M14 1 80 Nm (8.0 m·kgf, 58 ft·lbf)
Connecting arm bolt (frame side) M14 1 80 Nm (8.0 m·kgf, 58 ft·lbf)
Swingarm and brake hose holder
screwM5 4 3.5 Nm (0.35 m·kgf, 2.5 ft·lbf)
Drive chain tensioner bolt (upper
side)M8 1 16 Nm (1.6 m·kgf, 12 ft·lbf) ITEMThread
sizeQ’ty TIGHTENING TORQUES Remarks
LT
LT
LT

LUBRICATION POINTS AND LUBRICANT TYPES
2-21
EASB111060CHASSISCylinder head cover gasketThree Bond
No.1215®
Crankcase mating surfaceThree Bond
No.1215®
Stator assembly lead grommetThree Bond
No.1215®
Lubrication point Lubricant types
Upper bearings (steering head)
Upper bearings and bearing race cover (steering head)
Lower bearings and oil seal lip (steering head)
Steering stem threads and nut contacting surface
Pivot shaft bearing
Swingarm pivot portion (collar side surface and thrust bearing)
Swingarm pivot portion (collar outer surface)
Swingarm pivot portion (oil seal lip)
Pivot shaft outer surface
Relay arm bearing and oil seal lip
Relay arm thrust washer surface (both sides)
Relay arm collar outer surface and bolt outer surface
Relay arm bolt threads (swingarm side)
Connecting arm bearing and oil seal lip
Connecting arm collar outer surface and bolt outer surface
Rear shock absorber assembly collar outer surface and dust seal lip (upper
side)
Rear shock absorber assembly bearing and dust seal lip (lower side)
Brake pedal pivot portion (O-ring and bolt outer surface)
Front wheel oil seal lip
Front wheel axle outer surface
Rear wheel oil seal lip
Rear wheel axle outer surface
Push rod contacting portion (front brake master cylinder)
Front brake lever bolt outer surface
Clutch lever sliding surface and bolt outer surface
Clutch lever position adjuster end
Clutch lever adjuster rubber lip
Clutch cable end (clutch lever side)
Tube guide (throttle grip) inner surface and throttle cable end
Front brake caliper piston
Front brake caliper piston sealLubrication point Lubricant types
LS
LS
LS
LS
M
M
M
M
M
M
M
M
M
M
M
M
M
LS
LS
LS
LS
LS
S
S
LS
LS
LS
LS
LS
S

LUBRICATION POINTS AND LUBRICANT TYPES
2-22
Front brake caliper dust seal
Front brake caliper piston outer surface
Front brake caliper pin bolt and boot
Front brake master cylinder push rod end
Front brake master cylinder kit
Rear brake caliper piston
Rear brake caliper piston seal
Rear brake caliper dust seal
Rear brake caliper piston outer surface
Rear brake caliper pin bolt and boot
Rear brake master cylinder push rod end
Rear brake master cylinder kitLubrication point Lubricant typesS
S
S
S
S
S
S

CABLE ROUTING DIAGRAM
2-36
1. Throttle cable
2. Clutch cable
3. Plastic band
4. Engine stop switch lead
5. Launch control switch lead
6. Front brake hose
7. Brake hose guide
8. Number plate
A. Number plate band
B. Pass the clutch cable to the rear of the number
plate band.
C. Clamp the engine stop switch lead and the
launch control switch lead to the handlebar by the
plastic band. Do not cut the end of the plastic
band.
D. Pass the engine stop switch lead and the launch
control switch lead between the head pipe and
the cable guide.
E. Pass the front brake hose to the front of the num-
ber plate.
F. 40°±10°
G. Vertical direction
H. Pass the clutch cable to the guide in the number
plate.

CABLE ROUTING DIAGRAM
2-40
1. Brake master cylinder
2. Brake hose holder
3. Brake hoses
A. While installing the brake hose, direct a bend in
its pipe portion as shown, and bring it into contact
with the projection on the brake caliper.
B. Pass the brake hose into the brake hose holders.
C. If the brake hose interferes with the rear shock
absorber, correct its twist.
D. While installing the brake hose, direct a bend in
its pipe portion as shown, and bring it into contact
with the projection on the brake master cylinder.

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 VALVE 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 .................................... 3-11
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..................................................... 3-14
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........................................................................................................ 3-22
BLEEDING THE BRAKE SYSTEM .......................................................... 3-22
CHECKING THE BRAKE HOSE .............................................................. 3-23
ADJUSTING THE FRONT BRAKE .......................................................... 3-23
ADJUSTING THE REAR BRAKE ............................................................. 3-24
CHECKING THE FRONT BRAKE PADS ................................................. 3-24
CHECKING THE REAR BRAKE PADS ................................................... 3-26
CHECKING THE REAR BRAKE PAD INSULATOR ................................ 3-27
CHECKING THE BRAKE FLUID LEVEL.................................................. 3-27
ADJUSTING THE DRIVE CHAIN SLACK ................................................ 3-28
CHECKING THE FRONT FORK LEGS ................................................... 3-29
CHECKING THE FRONT FORK PROTECTOR GUIDE .......................... 3-29
CLEANING THE FRONT FORK OIL SEAL AND DUST SEAL ................ 3-29
AIR BLEEDING FROM FRONT FORK .................................................... 3-30
ADJUSTING THE FRONT FORK LEGS .................................................. 3-30
CHECKING THE SWINGARM OPERATION ........................................... 3-31
CHECKING THE REAR SUSPENSION ................................................... 3-31
ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLY ................... 3-31
CHECKING THE TIRES ........................................................................... 3-34
CHECKING AND TIGHTENING THE SPOKES ....................................... 3-34
CHECKING THE WHEELS ...................................................................... 3-34

MAINTENANCE INTERVALS
3-5
BRAKE(S)
Adjust lever posi-
tion and pedal
height
Lubricate pivot
point
Check brake disc
surface
Check fluid level
and leakage
Retighten brake
disc bolts, caliper
bolts, master cylin-
der bolts and union
boltsCheck for tightening torques.
Replace pads
Replace brake flu-
idEvery one year
SWINGARM
Inspect, lube and
retightenMolybdenum disulfide grease
RELAY ARM, CON-
NECTING ROD
Inspect, lube and
retightenMolybdenum disulfide grease
STEERING HEAD
Inspect free play
and retightenCheck for tightening torques.
Clean and lube After rain ride
Replace bearings
TIRE, WHEELS
Inspect air pres-
sure, wheel run-
out, tire wear and
spoke looseness
Retighten sprocket
bolt
Check the bearing
Replace bearings
Lubricate Lithium-soap-based greaseITEMAfter
break-
inEvery
race
(about
2.5
hours)Every
third
(about
7.5
hours)Every
fifth
(about
12.5
hours)As re-
quiredRemarks

MAINTENANCE INTERVALS
3-6
DRIVE CHAIN Use chain oil.
Clean, lubricate,
slack, alignment
Replace
DRIVE CHAIN
GUIDE
Inspect Inspect wear.
DRIVE CHAIN
GUIDE AND DRIVE
CHAIN SUPPORT
Replace
CABLES
Routing (Connec-
tion)
Check and grease
Check and clean
throttle cableCheck throttle cables on the
throttle body for dirt and wear.
LEVERS
Adjust clutch lever
free play
KICKSTARTER LE-
VER, BRAKE PED-
AL, FOOTREST
Lubricate
OUTSIDE NUTS
AND BOLTS
Retighten Refer to “TORQUE-CHECK
POINTS” on page 1-24. 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
EASB111066
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.
EASB111067GENERAL 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.ITEM inspect Page
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.1-21
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/HousingCheck 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.3-22 – 28
Drive chainCheck drive chain slack and alignment. Check that
the drive chain is lubricated properly.3-28 – 29
4-66 – 67
WheelsCheck for excessive wear and tire pressure. Check
for loose spokes and have no excessive play.3-34
SteeringCheck that the handlebar can be turned smoothly and
have no excessive play.3-35 – 36
Front forks and rear
shock absorberCheck that they operate smoothly and there is no oil
leakage.3-29 – 33
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.3-14
Rear wheel sprocketCheck that the rear wheel sprocket tightening bolt is
not loose.4-8 – 9
Lubrication Check for smooth operation. Lubricate if necessary. 3-12, 3-36
Bolts and nutsCheck the chassis and engine for loose bolts and
nuts.1-24 – 25
Lead connectorsCheck that the AC magneto, ECU and ignition coil are
connected tightly.1-10 – 12
SettingsIs 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

CHASSIS
3-22
EASB111088
CHASSIS
EASB111089BLEEDING THE BRAKE SYSTEMEWA13100
WARNING
Bleed the brake system whenever:
• The system is disassembled.
• A brake hose is loosened, disconnected,
or replaced.
• The brake fluid level is very low.
• Brake operation is faulty.
1. Remove:
• Brake master cylinder cap
• Reservoir diaphragm
• Reservoir float (front brake)
• Protector (rear brake)
TIP
• Be careful not to spill any brake fluid or allow
the reservoir to overflow.
• Make sure that there is enough brake fluid be-
fore applying the brake. Ignoring this precau-
tion could allow air to enter the brake system,
considerably lengthening the bleeding proce-
dure.
• If bleeding is difficult, it may be necessary to
let the brake fluid settle for a few hours. Re-
peat the bleeding procedure when the tiny
bubbles in the hose have disappeared.
2. Bleed the brake system.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Fill the reservoir to the proper level with the
recommended brake fluid.
b. Install the reservoir diaphragm.
c. Connect the plastic hose “1” to the bleed
screw “2” securely, and place a container
under the end of the plastic hose.d. Slowly apply the brake several times.
e. Fully pull the brake lever or fully press down
the brake pedal and hold it in position.
f. Loosen the bleed screw.
TIP
Loosening the bleed screw will release the
pressure in the brake caliper and cause the
brake lever to contact the throttle grip or the
brake pedal to fully extend.
g. Tighten the bleed screw and then release
the brake lever or brake pedal.
h. Repeat steps (d) to (g) until all of the air bub-
bles have disappeared from the brake fluid
in the plastic hose.
TIP
During the procedure, keep adding brake fluid
to the reservoir.
ECA
NOTICE
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
i. Tighten the bleed screw.
j. Pour brake fluid to the reservoir up to the
specified level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-27.
EWA13110
WARNING
After bleeding the hydraulic brake system,
check the brake operation.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
1 2
A
A. Front
B. Rear
Bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
2
1B
T R..