2012 YAMAHA YFZ450 suspension

4-13
4
EBU18993Adjusting the front shock absorber as-
semblies The spring preload can be adjusted to suit the rid-
er’s weight and the riding conditions.
WARNING
EWB00400Always adjust the shock absorber assemblies
on the left and right side to the same setting.
Uneven adjustment can cause poor handling
and loss of stability, which could lead to an ac-
cident.
Adjust the spring preload as follows.
Turn the spring preload adjusting ring in direction
(a) to increase the spring preload and thereby
harden the suspension, and in direction (b) to de-
crease the spring preload and thereby soften the
suspension.
Align the appropriate notch in the adjusting ring
with the position indicator on the shock absorber.TIPA special wrench can be obtained at a Yamaha
dealer to make this adjustment.
1. Projection
2. Seat holder
1
2
1. Spring preload adjusting ring
2. Special wrench
3. Position indicator
1 2 3
4 5
(a)
(b) 1
2
3
U1PD60E0.book Page 13 Monday, June 13, 2011 2:57 PM

4-15
44. Remove the bolts, and then remove the air fil-ter case by disconnecting the air intake duct
from the carburetor. 5. Loosen the locknut.
6. Turn the spring preload adjusting nut in direc-
tion (a) to increase the spring preload and
thereby harden the suspension, and in direc-
tion (b) to decrease the spring preload and
thereby soften the suspension.
1. Hose
2. Clamp screw
3. Air intake duct
12
3
1. Bolt
2. Air filter case
2
1
U1PD60E0.book Page 15 Monday, June 13, 2011 2:57 PM

8-7
8
14*Chassis fasteners 
Make sure that all nuts, bolts, and screws are
properly tightened. √√√√√
15 *Shock absorber as-
semblies 
Check operation and correct if necessary.
 Check for oil leakage and replace if necessary. √√√
16 *Rear suspension re-
lay arm and con-
necting arm
pivoting points 
Check operation and correct if necessary. √√√√
17 *Steering shaft Lubricate with lithium-soap-based grease. √√√
18 *Steering system 
Check operation and repair or replace if damaged.
 Check toe-in and adjust if necessary. √√√√√
19 *Engine mount 
Check for cracks or other damage, and replace if
necessary. √√√
20 Engine oil 
Change.
 Check ATV for oil leakage, and correct if neces-
sary. √ √√√
21 Engine oil filter ele-
ment

Replace. √√√
22 Cooling system 
Check coolant level and ATV for coolant leakage,
and correct if necessary. √√√√√
 Replace coolant. Every 2 years
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev- er comes first month136612
km
(mi) 320
(200) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320U1PD60E0.book Page 7 Monday, June 13, 2011 2:57 PM

10-4
10
Rim size:9 x 8.0ATFront brake:Type:
Disc brake
Operation: Right hand operation
Specified brake fluid: DOT 4Rear brake:Type:Disc brake
Operation: Right foot operation
Specified brake fluid:
DOT 4Front suspension:Type:Double wishbone
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel: 230 mm (9.1 in)Rear suspension:Type:
Swingarm (link suspension)
Spring/shock absorber type: Coil spring/gas-oil damper
Wheel travel: 270 mm (10.6 in)
Electrical system:Ignition system:DC CDI
Charging system:
AC magnetoBattery:Model:GT7B-4
Voltage, capacity:
12 V, 6.5 AhHeadlight:Bulb type:Krypton bulbBulb voltage, wattage × quantity:Headlight:
12 V, 30.0/30.0 W × 2
Tail/brake light: 12 V, 5.0/21.0 W × 1
Neutral indicator light:
12 V, 1.7 W × 1
Coolant temperature warning light: 12 V, 1.7 W × 1Fuses:Main fuse:
15.0 A
U1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM

Maintenance and lubrication chart ................................. 8-5
Maintenance chart, emission control system ................. 8-3
Model label ................................................................... 11-2NNeutral indicator light ..................................................... 4-2OOwner’s manual and tool kit ........................................... 8-2PPanel, removing and installing ....................................... 8-9
Parking ........................................................................... 6-5
Parking brake free play, adjusting ................................ 8-37
Parking brake lever ........................................................ 4-6
Parking on a slope ......................................................... 6-6
Part locations ................................................................. 3-1RRiding your ATV ............................................................. 7-1SSafety information .......................................................... 2-1
Seat .............................................................................. 4-12
Shifting ........................................................................... 6-3
Shift pedal ...................................................................... 4-7
Shift pedal, checking .................................................... 8-45
Shock absorber assemblies, adjusting the front .......... 4-13
Shock absorber assembly, adjusting the rear .............. 4-14
Spark arrester, cleaning ............................................... 8-28
Spark plug, checking .................................................... 8-10
Specifications ............................................................... 10-1
Speed limiter .................................................................. 4-4
Starter (choke) ............................................................. 4-11
Start switch ..................................................................... 4-3
Steering shaft, lubricating ............................................. 8-47
Storage ........................................................................... 9-2 Suspension, lubricating the upper and lower arm
pivots ......................................................................... 8-46
Swingarm pivots, lubricating ........................................ 8-46
TTail/brake light bulb, replacing ..................................... 8-53
Throttle lever ........................................................... 4-3, 5-5
Throttle lever free play, adjusting ................................. 8-31
Tires ............................................................................... 5-5
Troubleshooting ........................................................... 8-55
Troubleshooting charts ................................................. 8-57VValve clearance ............................................................ 8-31
Vehicle identification number ....................................... 11-1WWheel hub bearings, checking ..................................... 8-45
Wheel, installing ........................................................... 8-55
Wheel, removing .......................................................... 8-54
U1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM