CHASSIS
3-26
h. Repeat steps (d) to (g) until all of the air
bubbles have disappeared from the brake
fluid in the plastic hose.
TIP
During the procedure, keep adding brake fluid to
the reservoir.
NOTICE
ECA24320
• Wipe off any brake fluid on the brake discs,
tires, wheels, etc.
• 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 3-24.
WARNING
EWA13110
After bleeding the hydraulic brake system,
check the brake operation.
EAM30481
DRIVE CHAIN SLACK
NOTICE
ECA13550
A drive chain that is too tight will overload
the engine and other vital parts, and one that
is too loose can skip and damage the swing-
arm or cause an accident. Therefore, keep
the drive chain slack within the specified lim-
its.
Checking the drive chain slack
1. Use a maintenance stand to raise the rear
wheel off the ground.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
2. Shift the transmission into the neutral posi-
tion.
3. Pull the drive chain up above the drive chain
guide installation bolt with a force of about 50
N (5.0 kgf, 37 lbf).
4. Check:
•
Drive chain slack “a”
Out of specification
Regulate.
TIP
Measure drive chain slack between the drive
chain guide and the bottom of the chain as
shown.
Adjusting the drive chain slack
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
1. Adjust:
•
Drive chain slack
a. Loosen the wheel axle nut “1”.
b. Loosen both locknuts “2”.
c. Turn the adjusting bolt “3” until the speci-
fied drive chain slack is obtained.
TIP
•
To maintain the proper wheel alignment, adjust
both sides evenly.
•
Push the rear wheel forward to make sure that
there is no clearance between the swingarm
end plates and the ends of the swingarm.
d. Tighten the wheel axle nut.
e. Tighten the drive chain puller locknut.
Bleed screw
6 N·m (0.6 kgf·m, 4.4 lb·ft)
T
R
.
.
Drive chain slack (Maintenance
stand)
50.0–60.0 mm (1.97–2.36 in)
Wheel axle nut
135 N·m (13.5 kgf·m, 100 lb·ft)
a
a
1
3
2
T
R
.
.
Summary of Contents for YZ450F 2021
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY ...
Page 10: ......
Page 44: ...MOTORCYCLE CARE AND STORAGE 1 32 ...
Page 61: ...TIGHTENING TORQUES 2 16 ...
Page 62: ...CABLE ROUTING DIAGRAM 2 17 EAM20152 CABLE ROUTING DIAGRAM Frame and engine left side view ...
Page 64: ...CABLE ROUTING DIAGRAM 2 19 Frame and engine right side view ...
Page 66: ...CABLE ROUTING DIAGRAM 2 21 Handlebar front view ...
Page 68: ...CABLE ROUTING DIAGRAM 2 23 Frame and engine top view ...
Page 70: ...CABLE ROUTING DIAGRAM 2 25 Frame and battery top view ...
Page 72: ...CABLE ROUTING DIAGRAM 2 27 Rear brake right side view ...
Page 74: ...CABLE ROUTING DIAGRAM 2 29 ...
Page 112: ...ELECTRICAL SYSTEM 3 36 ...
Page 148: ...REAR BRAKE 4 34 system Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM on page 3 25 ...
Page 189: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Connecting rod 2 Oil nozzle 3 Crankshaft ...
Page 191: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 5 1 Oil filter element 2 Oil pump 3 Oil strainer ...
Page 262: ...TRANSMISSION 5 76 ...
Page 272: ...WATER PUMP 6 9 ...
Page 282: ...THROTTLE BODY 7 9 ...
Page 289: ...IGNITION SYSTEM 8 6 ...
Page 290: ...ELECTRIC STARTING SYSTEM 8 7 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM ...
Page 294: ...CHARGING SYSTEM 8 11 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM ...
Page 297: ...CHARGING SYSTEM 8 14 ...
Page 298: ...FUEL INJECTION SYSTEM 8 15 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM ...
Page 321: ...FUEL INJECTION SYSTEM 8 38 ...
Page 322: ...FUEL PUMP SYSTEM 8 39 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM ...
Page 352: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15 ...
Page 362: ...CHASSIS 10 9 ...
Page 364: ......
Page 366: ......
Page 368: ...YZ450FM 2021 WIRING DIAGRAM B2W 2819U 11_W D indd 2 2020 02 05 10 21 39 ...