clutch YAMAHA YFZ450 2008 User Guide

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the transmission.

Always use the clutch when changing gears.
The engine, transmission and drive train are
not designed to withstand the shock of
forced shifting and can be damaged by shift-
ing without using the clutch.
EBU20670
Engine break-in
There is never a more important period in the life of
your engine than the first 20 hours of riding. For
this reason, you should read the following material
carefully.
Since the engine is brand new, do not put an ex-
cessive load on it for the first 20 hours. The various
parts in the engine wear and polish themselves to
the correct operating clearances. During this peri-
od, prolonged full-throttle operation or any condi-
tion that might result in engine overheating must
be avoided.
0–10 hours
Avoid prolonged operation above 1/2 throttle. Vary
the speed of the ATV regularly. Do not operate it at
one set throttle position.
10–20 hours
Avoid prolonged operation above 3/4 throttle. Rev
the engine through the gears freely, but do not use
full throttle at any time.
20 hours and beyond
The ATV can now be operated normally.CAUTION:

ECB00220
If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV.
EBU20721
Parking
When parking the ATV, stop the engine, shift into
first gear, apply the parking brake, and then turn
the fuel cock to “OFF”.

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EBU20860
Parking on a slope
WARNING

EWB00850
Avoid parking on hills or other inclines. Park-
ing on a hill or other incline could cause the
ATV to roll out of control, increasing the
chance of an accident. If you must park on an
incline, place the ATV transversely across the
incline, shift into first gear, stop the engine, ap-
ply the parking brake, and then block the front
and rear wheels with rocks or other objects.
Do not park the ATV at all on hills that are so
steep you could not walk up them easily.
1. Bring the ATV to a stop by applying the brakes
in first gear.
2. Stop the engine and release the clutch lever.
3. With the rear brake applied, apply the parking
brake and slowly release the brake pedal.
EBU20910
Accessories and loading
EBU20920
Accessories
Accessories can affect the handling and control of
your ATV. Keep the following in mind when consid-
ering an accessory or operating an ATV which has
accessories.
1. Locked position
1

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these components.
With the engine idling, pull the clutch lever to dis-
engage the clutch and shift into 1st gear, and then
release the parking brake. Open the throttle grad-
ually, and at the same time, release the clutch le-
ver slowly. Once the ATV has attained adequate
speed, release the throttle lever and at the same
time, quickly pull in the clutch lever and shift into
2nd gear. Open the throttle part way and gradually
release the clutch. Use this same procedure as
you move into the higher gears. Be sure to coordi-
nate the use of the throttle and shift pedal properly.
If the throttle is applied too abruptly or if the throttle
is not released during shifting, or if the shift pedal
is not released before applying the throttle, the
front wheels may lift off the ground, resulting in a
loss of directional control. Avoid higher speeds un-
til you are thoroughly familiar with the operation of
your ATV.
WARNING

EWB01720
Always open the throttle gradually and release
the clutch lever slowly. Otherwise, the ATV
could wheelie which would increase the
chance of an accident.CAUTION:

ECB00230
Do not shift gears without releasing the throt-
tle. Damage to the engine or drive train may oc-
cur.
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. As
you slow down, shift to a lower gear. Be sure that
the engine has sufficiently slowed before engaging
a lower gear. Improper use of the brakes or shifting
can cause the tires to lose traction, reducing con-
trol and increasing the possibility of an accident.WARNING
EWB01560
Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a low-
er gear when the engine speed is too high
could cause the wheels to stop rotating.
TURNING YOUR ATV
To achieve maximum traction on unpaved surfac-
es, the two rear wheels are mounted solidly on one
axle and turn together at the same speed. There-
fore, unless the wheel on the inside of the turn is al-
lowed to slip or lose some traction, the ATV will
resist turning. A special turning technique must be

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EBU21864
General maintenance and lubrication chart
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth 1 3 6 6 12
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 3201 Air filter element


Clean and replace if necessary.Every 20–40 hours (more often in wet or
dusty areas)
2
*
Clutch

Check operation and adjust if necessary.
√ √√√
3
*
Front brake


Check operation and correct if necessary.

Check fluid level and ATV for fluid leakage, and
correct if necessary.
√√√√√

Replace brake pads. Whenever worn to the limit
4
*
Rear brake

Check operation and correct if necessary.

Check fluid level and ATV for fluid leakage, and
correct if necessary.
√√√√√

Replace brake pads. Whenever worn to the limit
5
*
Brake hoses

Check for cracks or other damage, and replace if
necessary.
√√√√

Replace. Every 4 years
6
*
Parking brake

Check operation and adjust if necessary.
√√√√√
7
*
Wheels


Check runout and for damage, and replace if nec-
essary.
√ √√√
8
*
Tires


Check tread depth and for damage, and replace if
necessary.

Check air pressure and balance, and correct if
necessary.
√ √√√
9
*
Wheel hub bearings


Check for looseness or damage, and replace if
necessary.
√ √√√

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12. Install the crankcase engine oil drain bolt and
the engine oil tank drain bolt, and then tighten
them to the specified torques.
13. Pour the specified amount of the recommend-
ed engine oil through the engine oil tank filler
hole, and then install and tighten the engine oil
tank filler cap.
14. Pour the specified amount of the recommend-
ed engine oil through the crankcase engine oil
filler hole, and then install and tighten the
crankcase engine oil filler cap.NOTE:

Be sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.CAUTION:

ECB00300

In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
with a diesel specification of “CD” or oils of
a higher quality than specified. In addition,
Tightening torques:
Crankcase engine oil drain bolt:
20 Nm (2.0 m·kgf, 14 ft·lbf)
Engine oil tank drain bolt:
19 Nm (1.9 m·kgf, 14 ft·lbf)
Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter element replacement:
Quantity in oil tank:
1.55 L (1.64 US qt) (1.36 Imp.qt)
Quantity in crankcase:
0.20 L (0.21 US qt) (0.18 Imp.qt)
With oil filter element replacement:
Quantity in oil tank:
1.55 L (1.64 US qt) (1.36 Imp.qt)
Quantity in crankcase:
0.30 L (0.32 US qt) (0.26 Imp.qt)

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EBU24740
Brake light switches
The operation of the brake light switches must be
checked and, if necessary, adjusted at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
The brake light switch for the brake pedal can be
adjusted as follows, but the other brake light
switches should be adjusted by a Yamaha dealer.
NOTE:

The brake light switch is properly adjusted when
the brake light comes on just before braking takes
effect.
Turn the adjusting nut while holding the brake light
switch in place. To make the brake light come on
earlier, turn the adjusting nut in direction (a). To
make the brake light come on later, turn the adjust-
ing nut in direction (b).
EBU24820
Adjusting the clutch lever free play
The clutch lever free play must be checked and, if
necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
The clutch lever free play should measure 8.0–
13.0 mm (0.31–0.51 in) as shown. If the free play
is incorrect, adjust it as follows.
1. Brake light switch
2. Brake light switch adjusting nut
(a)
(b)1
2

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1. Loosen the locknut at the clutch lever.
2. To increase the clutch lever free play, turn the
adjusting bolt at the clutch lever in direction
(a), and to decrease it, turn the bolt in direction
(b).
3. Tighten the locknut at the clutch lever.
If the specified free play cannot be obtained,
proceed with the following steps.
4. Loosen the locknut at the clutch lever.
5. Fully turn the adjusting bolt at the clutch lever
in direction (a) to loosen the clutch cable.
6. Loosen the locknut at the crankcase.7. To increase the clutch lever free play, turn the
adjusting nut at the crankcase in direction (a),
and to decrease it, turn the nut in direction (b).
8. Tighten the locknut at the crankcase and the
clutch lever.NOTE:
If the specified free play cannot be obtained as de-
scribed above or if the clutch does not operate cor-
rectly, have a Yamaha dealer check the internal
clutch mechanism.
1. Clutch lever free play
2. Clutch lever free play adjusting bolt
1
(a)
(b)
2

1. Locknut
2. Clutch lever free play adjusting nut (crankcase)
(a)
(b)
2
1

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WARNING

EWB02130
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could re-
strict the operation of controls and lead to an
accident or injury.
EBU24921
Checking and lubricating the brake and
clutch levers
The operation of the brake and clutch levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
Brake lever
Clutch lever
Recommended lubricants:
Brake lever:
Silicone grease
Clutch lever:
Lithium-soap-based grease (all-purpose
grease)

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Engine oil quantity:
Without oil filter element replacement:
1.75 L (1.85 US qt) (1.54 Imp.qt)
Quantity in oil tank:
1.55 L (1.64 US qt) (1.36 Imp.qt)
Quantity in crankcase:
0.20 L (0.21 US qt) (0.18 Imp.qt)
With oil filter element replacement:
1.85 L (1.96 US qt) (1.63 Imp.qt)
Quantity in oil tank:
1.55 L (1.64 US qt) (1.36 Imp.qt)
Quantity in crankcase:
0.30 L (0.32 US qt) (0.26 Imp.qt)
Cooling system:
Coolant reservoir capacity (up to the maximum level mark):
0.29 L (0.31 US qt) (0.26 Imp.qt)
Radiator capacity (including all routes):
1.30 L (1.37 US qt) (1.14 Imp.qt)
Air filter:
Air filter element:
Wet element
Fuel:
Recommended fuel:
Premium unleaded gasoline only
Fuel tank capacity:
10.0 L (2.64 US gal) (2.20 Imp.gal)
Fuel reserve amount:
1.9 L (0.50 US gal) (0.42 Imp.gal)
Carburetor:
Manufacturer:
KEIHINType x quantity:
FCR39H x 1
Spark plug (s):
Manufacturer/model:
NGK/CR8E
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Clutch:
Clutch type:
Wet, multiple-disc
Transmission:
Primary reduction system:
Spur gear
Primary reduction ratio:
62/22 (2.818)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
38/14 (2.714)
Transmission type:
Constant mesh 5-speed
Operation:
Left foot operation
1st:
29/12 (2.416)
2nd:
27/14 (1.928)
3rd:
25/16 (1.562)
4th:
23/18 (1.277)

INDEX
A
Accessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-24
B
Battery .......................................................................... 8-45
Brake and clutch levers, checking and lubricating ....... 8-42
Brake and shift pedals, checking and lubricating ......... 8-43
Brake fluid, changing.................................................... 8-35
Brake fluid level, checking............................................ 8-32
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ...................... 8-36
Brake light switches ..................................................... 8-39
Brake pads, checking the front and rear ...................... 8-31
Brake pedal .................................................................... 4-5
Brake pedal position, checking .................................... 8-36
Brakes, front and rear .................................................... 5-4
C
Cables, checking and lubricating ................................. 8-41
Carburetor, adjusting.................................................... 8-29
Chassis fasteners........................................................... 5-8
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-5
Clutch lever free play, adjusting ................................... 8-39
Coolant ................................................................. 5-4
,
8-20
Coolant temperature warning light ................................. 4-1
D
Drive chain ..................................................................... 5-5
Drive chain, lubricating ................................................. 8-41
E
Engine break-in .............................................................. 6-5
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-30
Engine oil ....................................................................... 5-4
Engine oil and oil filter element .................................... 8-14
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-2
F
Fuel ........................................................................ 4-8
,
5-4
Fuel cock ........................................................................ 4-9
Fuel tank cap.................................................................. 4-7
Fuse, replacing............................................................. 8-46
H
Handlebar switches ........................................................ 4-2
Headlight beam, adjusting............................................ 8-49
Headlight bulb, replacing.............................................. 8-47
I
Identification numbers .................................................. 11-1
Indicator light and warning light...................................... 4-1
Instruments, lights and switches .................................... 5-8
K
Key identification number ............................................. 11-1