2014 YAMAHA YZ450F ABS

IMPORTANT INFORMATION
1-11
GASKETS, OIL SEALS AND O-RINGS
1. When overhauling the engine, replace all
gaskets and O-rings. All gasket surfaces, oil
seal lips, and O-rings must be cleaned so
that there may be no dust on them.
2. During assembly, always apply proper oil to
bearings and proper grease to oil seal lips
before installation.
EAS1SL1026LOCK WASHERS/PLATES AND COTTER
PINS
After removal, replace lock washers/plates “1”
and cotter pins with new ones. After the bolt or
nut has been tightened to specification, firmly
bend the lock tabs along a flat of the bolt or nut.
EAS1SL1027BEARINGS AND OIL SEALS
Install bearings “1” and oil seals “2” with their
manufacturer’s marks or size symbols facing
outward. During installation of an oil seal, make
sure that its main lip faces the oil chamber (the
target to be sealed). Before installation, always
apply a light coat of grease to the oil seal lip.
ECA13300
NOTICE
Do not spin a bearing with compressed air
because this will damage the bearing sur
-
faces.
EAS1SL1028CIRCLIPS
When assembling parts, always use new cir-
clips. During installation of a circlip, make sure
that the edge “2” of the circlip “1” is positioned
opposite to the force “3” that the circlip re
-
ceives. Install the circlip with its end aligned
with the center of the spline, without opening
the circlip more than necessary.
1. Oil
2. Lip
3. Spring
4. Grease

MAINTENANCE AFTER BREAK-IN
1-24
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.
EAS1SL1047MAJOR 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”.)
• Greasing and oiling
Always grease or oil the specified points.

TORQUE-CHECK POINTS
1-25
EAS1SL1048
TORQUE-CHECK POINTS
Frame constructionFrame to rear frame
Frame to engine protector
Combined seat and fuel tankFuel tank to frame
Engine mountingFrame to engine
Engine bracket to engine
Engine bracket to frame
SeatSeat to frame
SteeringSteering stem to handlebarSteering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
SuspensionFrontSteering stem to front forkFront fork to upper bracket
Front fork to lower bracket
RearLinkAssembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Mounting of rear shock absorberRear shock absorber and frame
Mounting of swingarmTightening of pivot shaft
Wheel (s)Mounting of wheelFrontTightening of wheel axle
Tightening of axle holder
Tightening of spoke nipple
RearTightening of wheel axle
Wheel to rear wheel sprocket
Tightening of spoke nipple
Brake(s)FrontBrake 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
RearBrake 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 systemFuel pump to fuel tank

CHASSIS SPECIFICATIONS
2-9
Brake disc thickness limit 2.5 mm (0.10 in)
Brake pad lining thickness (inner) 4.4 mm (0.17 in)
Limit 1.0 mm (0.04 in)
Brake pad lining thickness (outer) 4.4 mm (0.17 in)
Limit 1.0 mm (0.04 in)
Master cylinder inside diameter 9.52 mm (0.37 in)
Caliper cylinder inside diameter 22.65 mm  2 (0.89 in  2)
Recommended brake fluid DOT 4
Rear brake
Type Single disc brake
Operation Right foot operation
Rear disc brake
Disc outside diameter  thickness 245.0  4.0 mm (9.65  0.16 in)
Brake disc thickness limit 3.5 mm (0.14 in)
Brake disc deflection limit 0.15 mm (0.0059 in)
Brake pad lining thickness (inner) 6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
Brake pad lining thickness (outer) 6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
Master cylinder inside diameter 11.0 mm (0.43 in)
Caliper cylinder inside diameter 25.40 mm  1 (1.00 in  1)
Recommended fluid DOT 4
Steering
Steering bearing type Taper roller bearing
Center to lock angle (left) 43.0 °
Center to lock angle (right) 43.0 °
Front suspension
Type Telescopic fork
Spring/shock absorber type Coil spring/oil damper
Front fork travel 310.0 mm (12.20 in)
Fork spring free length 497.0 mm (19.57 in)
Limit 492.0 mm (19.37 in)
Installed length 497.0 mm (19.57 in)
Spring rate K1 4.90 N/mm (0.50 kgf/mm, 27.98 lbf/in) (USA) 
(CAN)
4.70 N/mm (0.48 kgf/mm, 26.84 lbf/in) (EUR) 
(JPN) (AUS) (NZL) (ZAF)
Spring stroke K1 0.0–310.0 mm (0.00–12.20 in)
Inner tube outer diameter 48.0 mm (1.89 in)
Inner tube bending limit 0.2 mm (0.01 in)
Optional spring available Yes
Recommended oil Suspension oil S1
Standard oil amount 531.0 cm3 (17.95 US.oz, 18.73 Imp.oz) (USA) 
(CAN)
551.0 cm3 (18.63 US.oz, 19.43 Imp.oz) (EUR) 
(JPN) (AUS) (NZL) (ZAF)
Rebound damping adjusting positions
* Position in which the adjuster is turned in finger tight
Minimum 20 click (s) out*
Standard 8 click (s) out*
Maximum (hard) Fully turned in

CHASSIS SPECIFICATIONS
2-10
Compression damping adjusting positions
* Position in which the adjuster is turned in finger tight
Minimum 20 click (s) out*
Standard 9 click (s) out* (USA) (CAN)
8 click (s) out* (EUR) (JPN) (AUS) NZL) (ZAF)
Maximum (hard) Fully turned in
Rear suspension
Type Swingarm (link suspension)
Spring/shock absorber type Coil spring/gas-oil damper
Rear shock absorber assembly travel 132.0 mm (5.20 in)
Spring free length 275.0 mm (10.83 in)
Spring rate K1 58.00 N/mm (5.91 kgf/mm, 331.18 lbf/in) (USA) 
(CAN)
56.00 N/mm (5.71 kgf/mm, 319.76 lbf/in) (EUR) 
(JPN) (AUS) (NZL) (ZAF)
Spring stroke K1 0.0–150.0 mm (0.00–5.91 in)
Optional spring available Yes
Enclosed gas/air pressure (STD) 980 kPa (9.8 kgf/cm2, 139.4 psi)
Spring installed length
Minimum Position in which the spring is turned in 1.5 mm 
(0.06 in) from its free length.
Standard Position in which the spring is turned in 10 mm 
(0.39 in) from its free length.
Maximum Position in which the spring is turned in 18 mm 
(0.71 in) from its free length.
Rebound damping adjusting positions
* Position in which the adjuster is turned in finger tight
Minimum 30 click (s) out*
Standard 14 click (s) out* (USA) (CAN)
12 click (s) out* (EUR) (JPN) (AUS) (NZL) 
(ZAF)
Maximum Fully turned in
Compression damping adjusting positions 
(for fast compression damping)
* Position in which the adjuster is turned in finger tight
Minimum 2 turn (s) out*
Standard 1-1/2 turn (s) out* (USA) (CAN)
1-1/8 turn (s) out* (EUR) (JPN) (AUS) (NZL) 
(ZAF)
Maximum Fully turned in
Compression damping adjusting positions 
(for slow compression damping)
* Position in which the adjuster is turned in finger tight
Minimum 20 click (s) out*
Standard 12 click (s) out* (USA) (CAN)
10 click (s) out* (EUR) (JPN) (AUS) (NZL) 
(ZAF)
Maximum Fully turned in
Swingarm
Swingarm end free play limit (radial) 1.0 mm (0.04 in)
Swingarm end free play limit (axial) 0.2–0.9 mm (0.01–0.04 in)

TIGHTENING TORQUES
2-19
Rear brake disc boltM6 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 bolt M4 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
locknut M8 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) M 10 1 59 Nm (5.9 m·kgf, 43 ft·lbf)
Engine mounting bolt (lower side) M 10 1 53 Nm (5.3 m·kgf, 38 ft·lbf)
Engine bracket bolt (upper side) M8 4 34 Nm (3.4 m·kgf, 25 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 32 Nm (3.2 m·kgf, 23 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 bolt M10 1 56 Nm (5.6 m·kgf, 41 ft·lbf)
Rear shock absorber assembly low-
er bolt M10 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
screw M5 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)
Drive chain tensioner bolt (lower
side) M8 1 16 Nm (1.6 m·kgf, 12 ft·lbf)
Drive chain support bolt M6 1 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
ITEM
Thread
size Q’ty TIGHTENING TORQUES RemarksLT
LT

LUBRICATION POINTS AND LUBRICANT TYPES
2-23
CHASSIS
Lubrication pointLubricant 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 seal
Front brake caliper dust seal
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
LS
LS
LS
LS
M
M
M
M
M
M
M
M
M
M
M
M
M
LS
LS
LS
LS
LS
LS
LS
LS
LS
LS
LS
LS
S
S
S
S

CABLE ROUTING DIAGRAM
2-42
1. Brake master cylinder
2. Brake hose holder3. 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.