2010 YAMAHA YZ450F relay

2-14
TIGHTENING TORQUES
△Driven sprocket and wheel hub M8 × 1.25 6 42 4.2 30
△Nipple (spoke) — 72 3 0.3 2.2
△Disc cover and rear brake caliper M6 × 1.0 2 10 1.0 7.2
△Protector and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Drive chain puller adjust bolt and locknut M8 × 1.25 2 21 2.1 15
Engine mounting:
△Upper engine bracket and frame M8 × 1.25 4 45 4.5 32
△Front engine bracket and frame M8 × 1.25 4 34 3.4 24
△Engine and engine bracket (front) M10 × 1.25 1 53 5.3 38
△Engine and engine bracket (upper) M10 × 1.25 2 45 4.5 32
△Engine and frame (lower) M10 × 1.25 1 53 5.3 38
△Engine guard M6 × 1.0 1 10 1.0 7.2
Lower engine guard M6 × 1.0 3 10 1.0 7.2
△Pivot shaft and nut M16 × 1.5 1 85 8.5 61
△Relay arm and swingarm M14 × 1.5 1 70 7.0 50
△Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
△Connecting rod and frame M14 × 1.5 1 80 8.0 58
△Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
△Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
△Rear shock absorber locknut M60 × 1.5 1 30 3.0 22
△Rear frame and frame (upper) M8 × 1.25 1 32 3.2 23
△Rear frame and frame (lower) M8 × 1.25 2 32 3.2 23
△Swingarm and brake hose holder M5 × 0.8 4 3 0.3 2.2
Upper drive chain tensioner M8 × 1.25 1 16 1.6 11
Lower drive chain tensioner M8 × 1.25 1 16 1.6 11
Drive chain support and swingarm M6 × 1.0 3 7 0.7 5.1
△Seal guard and swingarm M5 × 0.8 3 4 0.4 2.9
△Fuel tank mounting boss and frame M10 × 1.25 1 20 2.0 14
△Fuel tank (front) M6 × 1.0 2 9 0.9 6.5
Fuel tank bracket (front) M6 × 1.0 4 7 0.7 5.1
△Fuel tank (rear) M6 × 1.0 2 9 0.9 6.5
Fuel tank bracket (rear) M6 × 1.0 2 7 0.7 5.1
△Fuel pump M5 × 0.8 6 4 0.4 2.9
Fuel tank side cover M6 × 1.0 4 7 0.7 5.1
Fuel tank and seat set bracket M6 × 1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M6 × 1.0 4 7 0.7 5.1
Seat M8 × 1.25 2 22 2.2 16
△Side cover M6 × 1.0 4 7 0.7 5.1
Heat protector M5 × 0.8 2 4 0.4 2.9
△Air scoop and fuel tank M6 × 1.0 2 9 0.9 6.5
△Air scoop and air duct M6 × 1.0 2 7 0.7 5.1
radiator and radiator guard M6 × 1.0 2 10 1.0 7.2
△Air scoop and radiator guard M6 × 1.0 2 7 0.7 5.1
△Front fender M6 × 1.0 4 10 1.0 7.2Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb

3-4
MAINTENANCE INTERVALS
SWINGARM
Inspect, lube and retighten●●Molybdenum disulfide grease
RELAY ARM, CONNECTING
ROD
Inspect, lube and retighten●●Molybdenum disulfide grease
STEERING HEAD
Inspect free play and retighten●●
Clean and lube●Lithium base grease
Replace bearing●
TIRE, WHEELS
Inspect air pressure, wheel run-
out, tire wear and spoke loose-
ness●●
Retighten sprocket bolt●●
Inspect bearings●
Replace bearings●
Lubricate●Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection●●Yamaha cable lube or SAE 10W-40
motor oil
Lubricate●● ItemAfter
break-
inEvery
race
(about
2.5
hours)
Every
third
(about
7.5
hours)Every
fifth
(about
12.5
hours)
As re-
quiredRemarks

5-32
SWINGARM
SWINGARM
REMOVING THE SWINGARM
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the engine.Refer to "HANDLING NOTE".
Brake hose holder Refer to "FRONT BRAKE AND REAR
BRAKE" section.
Rear brake caliperRefer to "FRONT BRAKE AND REAR
BRAKE" section.
Bolt (brake pedal) Shift the brake pedal backward.
Drive chain
1 Drive chain support 1
2 Lower chain tensioner 1
3 Bolt (rear shock absorber-relay arm) 1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1

5-33
SWINGARM
DISASSEMBLING THE SWINGARM
Order Part name Q'ty Remarks
1 Relay arm 1
2 Connecting rod 1
3 Collar 2
4 Oil seal 2
5 Thrust bearing 2
6 Bushing 2
7 Oil seal 8
8 Bearing 10 Refer to removal section.

5-34
SWINGARM
HANDLING NOTE
Support the machine securely so
there is no danger of it falling over.
REMOVING THE BEARING
1. Remove:
• Bearing "1"
Remove the bearing by pressing its
outer race.
CHECKING THE SWINGARM
1. Inspect:
• Bearing "1"
• Bushing "2"
Free play exists/unsmooth revolu-
tion/rust →Replace bearing and
bushing as a set.
2. Inspect:
• Oil seal "3"
Damage→Replace.
CHECKING THE RELAY ARM
1. Inspect:
• Bearing "1"
•Collar "2"
Free play exists/unsmooth revolu-
tion/rust → Replace bearing and
collar as a set.
2. Inspect:
• Oil seal "3"
Damage→Replace.CHECKING THE CONNECTING
ROD
1. Inspect:
•Bearing "1"
• Collar "2"
Free play exists/unsmooth revolu-
tion/rust →Replace bearing and
collar as a set.
2. Inspect:
• Oil seal "3"
Damage→Replace.
INSTALLING THE BEARING AND
OIL SEAL
1. Install:
•Bearing "1"
• Oil seal "2"
To swingarm.
• Apply the molybdenum disulfide
grease on the bearing when install-
ing.
• Install the bearing by pressing it on
the side having the manufacture's
marks or numbers.
• First install the outer and then the
inner bearings to a specified depth
from inside.
2. Install:
• Bearing "1"
• Washer "2"
• Oil seal "3"
To relay arm.
• Apply the molybdenum disulfide
grease on the bearing when install-
ing.
• Install the bearing by pressing it on
the side having the manufacture's
marks or numbers.
• Apply the molybdenum disulfide
grease on the washer.
3. Install:
• Bearing "1"
• Oil seal "2"
To connecting rod.
• Apply the molybdenum disulfide
grease on the bearing when install-
ing.
• Install the bearing by pressing it on
the side having the manufacture's
marks or numbers.
Installed depth of bear-
ings:
Outer "a": Zero mm
(Zero in)
Inner "b": 6.5 mm (0.26
in)
Installed depth of bear-
ings "a":
Zero mm (Zero in)
Installed depth of bear-
ings "a":
Zero mm (Zero in)

5-35
SWINGARM
INSTALLING THE SWINGARM
1. Install:
• Bushing "1"
• Thrust bearing "2"
• Oil seal "3"
•Collar "4"
To swingarm "5".
Apply the molybdenum disulfide
grease on the bushings, thrust bear-
ings, oil seal lips and contact surfaces
of the collar and thrust bearing.
2. Install:
•Collar "1"
• Washer "2"
To relay arm "3".
Apply the molybdenum disulfide
grease on the collars and oil seal lips.
3. Install:
•Collar "1"
To connecting rod "2".
Apply the molybdenum disulfide
grease on the collar and oil seal lips.
4. Install:
• Connecting rod "1"
• Bolt (connecting rod) "2"
• Washer "3"
• Nut (connecting rod) "4"
To relay arm "5".
Apply the molybdenum disulfide
grease on the bolt.
5. Install:
• Relay arm "1"
• Bolt (relay arm) "2"
• Washer "3"
• Nut (relay arm) "4"
To swingarm.
• Apply the molybdenum disulfide
grease on the bolt circumference
and threaded portion.
• Do not tighten the nut yet.
6. Install:
• Swingarm "1"
• Pivot shaft "2"
• Apply the molybdenum disulfide
grease on the pivot shaft.
• Insert the pivot shaft from right side.
7. Check:
• Swingarm side play "a"
Free play exists→Replace thrust
bearing.
• Swingarm up and down move-
ment "b"
Unsmooth movement/binding/
rough spots →Grease or replace
bearings, bushings and collars.
8. Install:
• Bolt (connecting rod) "1"
• Washer "2"
• Nut (connecting rod) "3"
• Apply the molybdenum disulfide
grease on the bolt.
• Do not tighten the nut yet.
9. Install:
• Bolt (rear shock absorber-relay
arm) "1"
• Nut (rear shock absorber-relay
arm) "2"
Apply the molybdenum disulfide
grease on the bolt.
Nut (connecting rod):
80 Nm (8.0 m•kg, 58
ft•lb)
Pivot shaft:
85 Nm (8.5 m•kg, 61
ft•lb)
Nut (rear shock absorb-
er-relay arm):
53 Nm (5.3 m•kg, 38
ft•lb)

5-36
SWINGARM
10. Tighten:
• Nut (connecting rod) "1"
11. Tighten:
• Nut (relay arm) "1"
12. Install:
• Bolt (lower chain tensioner) "1"
• Washer "2"
•Collar "3"
• Lower chain tensioner "4"
• Nut (lower chain tensioner) "5"13. Install:
• Drive chain support "1"
• Drive chain support cover "2"
• Bolt {drive chain support [L = 50
mm (1.97 in)]} "3"
• Nut (drive chain support) "4"
• Bolt {drive chain support cover [L
= 10 mm (0.39 in)]} "5" Nut (connecting rod):
80 Nm (8.0 m•kg, 58
ft•lb)
Nut (relay arm):
70 Nm (7.0 m•kg, 50
ft•lb)
Nut (lower chain tension-
er):
16 Nm (1.6 m•kg, 11
ft•lb)
Nut (drive chain sup-
port):
7 Nm (0.7 m•kg, 5.1
ft•lb)
Bolt (drive chain support
cover):
7 Nm (0.7 m•kg, 5.1
ft•lb)

5-37
REAR SHOCK ABSORBER
REAR SHOCK ABSORBER
REMOVING THE REAR SHOCK ABSORBER
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the engine.Refer to "HANDLING NOTE".
Seat Refer to "SEAT AND SIDE COVERS" section
in the CHAPTER 4.
Silencer Refer to "EXHAUST PIPE AND SILENCER"
section in the CHAPTER 4.
1 Bolt (rear shock absorber-relay arm) 1 Hold the swingarm.
2 Bolt (rear shock absorber-frame) 1
3 Rear shock absorber 1
4 Locknut 1 Only loosening.
5 Adjuster 1 Only loosening.
6 Lower spring guide 1
7 Upper spring guide 1
8 Spring (rear shock absorber) 1
9 Bearing 2 Refer to removal section.