clutch YAMAHA YFZ450 2019 User Guide

6-4
6
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.
EBU20674Engine break-inThere is never a more important period in the life
of your engine than the first 320 km (200 mi) or 20
hours of operation. For this reason, you should fol-
low the engine break-in instructions carefully.
Since the engine is brand new, do not put an ex-
cessive load on it for the first 320 km (200 mi) or
20 hours. During this period the various parts in
the engine wear and polish themselves to the cor-
rect operating clearances. Avoid prolonged full-
throttle operation or any condition that might re-
sult in engine overheating.
0–160 km (0–100 mi) or 0–10 hours
Avoid prolonged operation above 1/2 throttle.
Vary the speed of the ATV regularly. Do not oper-
ate it at one set throttle position. 160–320 km (100–200 mi) or 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.
320 km (200 mi) or 20 hours and beyond
The ATV can now be operated normally.
NOTICEECB00221If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV. EBU26762ParkingWhen parking the ATV, shift into first gear, stop
the engine, and then apply the parking brake.
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7-11
7Select a large, flat, unpaved area to become famil-
iar with your ATV. Make sure that this area is free
of obstacles and other riders. You should practice
control of the throttle, brakes, shifting procedures,
and turning techniques in this area before trying
more difficult terrain.
Set the parking brake and follow the instruction on
page 6-1 to start the engine. Once it has warmed
up you are ready to begin riding your ATV. As you
get on the ATV, be sure not to accidentally move
the shift pedal. With the engine idling, pull the
clutch lever to disengage the clutch and shift into
1st gear, and then release the parking brake.
Open the throttle gradually, and at the same time,
release the clutch lever slowly. Once the ATV has
attained adequate speed, release the throttle lever
and at the same time, quickly pull in the clutch le-
ver and shift into 2nd gear. Open the throttle part
way and gradually release the clutch.
WARNING!
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 con- trol.
[EWB02632]

NOTICE: Do not shift gears without
releasing the throttle. Damage to the engine or
drive train may occur.
[ECB01072]
Use this same procedure as you move into the
higher gears. Be sure to coordinate the use of the
throttle and shift pedal properly.
Avoid higher speeds until you are thoroughly fa-
miliar with the operation of your ATV.
When slowing down or stopping, release the
throttle 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 en-
gaging a lower gear. Improper use of the brakes or
shifting can cause the tires to lose traction, reduc-
ing control and increasing the possibility of an ac-
cident.
TURNING YOUR ATV
WARNING
EWB01772Always follow proper procedures for turning as
described in this Owner’s Manual. Practice
turning at low speeds before attempting to turn
at faster speeds. Do not turn at speeds too fast
for your skills or the conditions. ATV could go
out of control, causing a collision or overturn.
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8-5
8
EBU2186EPeriodic maintenance chart: General maintenance and lubricationTIPFor ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals in-
stead.
 For odometer or hour meter-equipped vehicles, follow the month maintenance interval if the ATV isn’t
ridden for the stated mileage or engine operating hours.
 Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills. 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 80 160 160 320
1 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
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8-19
811. Install the crankcase engine oil drain bolt, the
engine oil tank drain bolt and their new gas-
ket, and then tighten the bolts to their speci-
fied torques.
12. Refill with the specified amount of the recom- mended engine oil through the engine oil tank
filler hole.
TIPBe sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.
NOTICEECB00301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,
do not use oils labeled “ENERGY CONSERV-
ING II” or higher.
 Make sure that no foreign material enters the
crankcase. 13. Check the engine oil tank filler cap O-ring for
damage, and replace it if necessary.
14. Install and tighten the engine oil tank filler cap.
15. Start the engine, and then let it idle for several minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
16. Turn the engine off, and then check the oil level and correct it if necessary.
17. Install the engine guard by installing the bolts, and then tighten them to the specified torque.
NOTICE: Be sure to apply LOCTITE
® to the
engine guard bolts before installing them.
[ECB00372]
Tightening torques: Crankcase engine oil drain bolt:20 N·m (2.0 kgf·m, 15 lb·ft)
Engine oil tank drain bolt: 20 N·m (2.0 kgf·m, 15 lb·ft)
Recommended oil: See page 10-1.
Oil quantity: Without oil filter element replacement:1.40 L (1.48 US qt, 1.23 Imp.qt)
With oil filter element replacement: 1.45 L (1.53 US qt, 1.28 Imp.qt)
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8-35
8
EBU30155Adjusting the clutch lever free playPeriodically check the clutch lever free play and
adjust if necessary.1. To increase the clutch lever free play, turn the clutch lever free play adjusting nut at the
clutch lever in direction (a), and to decrease it,
turn the nut in direction (b).
If the specified free play cannot be obtained,
proceed with the following steps. 2. Fully turn the adjusting nut at the clutch lever
in direction (a) to loosen the clutch cable.
3. Slide back the rubber cover at the clutch ca- ble.
4. Loosen the locknut.
5. To increase the clutch lever free play, turn the clutch lever free play adjusting nut located to-
wards the center of the cable in direction (a),
and to decrease it, turn the nut in direction (b).
6. Tighten the locknut.
7. Slide the rubber cover to its original position.1. Clutch lever free play
2. Clutch lever free play adjusting nut (clutch lever)Clutch lever free play: 8.0–13.0 mm (0.31–0.51 in)
1
(a)
(b)
2
1. Locknut
2. Clutch lever free play adjusting nut (clutch cable)
3. Rubber cover
1
2
3
(b)
(a)
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8-36
8
TIPIf the specified free play cannot be obtained as de-
scribed above or if the clutch does not operate
correctly, have a Yamaha dealer check the internal
clutch mechanism. EBU26867Drive chain slackThe drive chain slack should be checked before
each ride and adjusted if necessary.TIPWhen checking and adjusting the drive chain
slack, there should be no weight on the ATV and
all tires must be touching the ground. To check the drive chain slack1. Park the ATV on a level surface.
2. Move the ATV back and forth to locate the tightest portion of the drive chain, and then
measure the drive chain slack as shown. 3. If the drive chain slack is incorrect, adjust it as
follows.
To adjust the drive chain slack 1. Park the ATV on a level surface.
2. Loosen the rear wheel axle pinch bolts.
3. Insert a rod of a diameter of 8 mm (0.3 in) and a length of 10 cm (4 in) into one of the holes in
the drive chain tensioner as shown.
Drive chain slack: 25.0–35.0 mm (0.98–1.38 in)
1. Drive chain slack
1
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8-39
8essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
WARNING
EWB02582
Inspect cables frequently and replace if
damaged. Corrosion can result when the ca-
ble sheaths become damaged, and cables
can also become frayed or kinked, which
could restrict the operation of controls and
lead to an accident or injury.
 Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or
do not work smoothly, you could be unable
to control the ATV, which could lead to an
accident or collision.
EBU24923Checking and lubricating the brake
and clutch leversThe operation of the brake and clutch levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
Brake lever
Recommended lubricant:
Yamaha cable lubricant or other suitable cable lubricantRecommended lubricants: Brake lever:Silicone grease
Clutch lever: Lithium-soap-based grease
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8-40
8
Clutch lever
EBUM0171Checking the shift pedalThe operation of the shift pedal should be
checked before each ride. If operation is not
smooth, have a Yamaha dealer check the vehicle.EBU28872Checking and lubricating the brake
pedalThe operation of the brake pedal should be
checked before each ride, and the pedal pivot
should be lubricated if necessary.
EBU24964Checking the wheel hub bearingsThe front and rear wheel hub bearings must be
checked at the intervals specified in the periodic
maintenance and lubrication chart. If there is play
in a wheel hub or if a wheel does not turn smooth-
ly, have a Yamaha dealer check the wheel hub
bearings.Recommended lubricant:
Lithium-soap-based grease
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10-3
10
Secondary reduction ratio:2.714 (38/14)
Final drive: Chain
Clutch type:
Wet, multiple-disc
Transmission type: 5-speed
Gear ratio: 1st: 2.500 (35/14)
2nd: 2.000 (30/15)
3rd:
1.632 (31/19)
4th: 1.333 (28/21)
5th: 1.095 (23/21)Front tire:Size:AT21 x 7R10
Manufacturer/model: MAXXIS/MS21Rear tire:Size:AT20 x 10R9
Manufacturer/model: MAXXIS/MS22Tire air pressure (measured on cold tires):Vehicle load:0.0–100.0 kg (0–220 lb) Recommended:
Front:
35.0 kPa (0.350 kgf/cm², 5.0 psi)
Rear: 35.0 kPa (0.350 kgf/cm², 5.0 psi)
Minimum: Front: 32.0 kPa (0.320 kgf/cm², 4.6 psi)
Rear: 32.0 kPa (0.320 kgf/cm², 4.6 psi)
Front wheel:Rim size:10 X 5.5ATRear wheel:Rim size:
9 X 8.0ATFront brake:Type:Hydraulic disc brakeRear brake:Type:Hydraulic disc brakeBrake fluid:Specified brake fluid:
DOT 4Front suspension:Type:Double wishbone
Spring:
Coil spring
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12-1
12
INDEX
AAccessories and loading ................................................ 6-5
Air filter element, cleaning ........................................... 8-21BBattery ......................................................................... 8-43
Brake and clutch levers, checking and lubricating ...... 8-39
Brake fluid, changing ................................................... 8-31
Brake fluid level, checking ........................................... 8-30
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ..................... 8-32
Brake light switches ..................................................... 8-34
Brake pads, checking the front and rear ..................... 8-29
Brake pedal .................................................................... 4-6
Brake pedal, checking and lubricating ........................ 8-40
Brake pedal height, checking ...................................... 8-32
Brakes .......................................................................... 8-28
Brakes, front and rear .................................................... 5-4
Brake/tail light .............................................................. 8-49CCables, checking and lubricating ................................ 8-38
Chassis fasteners .......................................................... 5-7
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-5
Clutch lever free play, adjusting .................................. 8-35
Coolant .................................................................5-4, 8-20
Coolant, changing ........................................................ 8-21
Coolant temperature warning light ................................ 4-2
Cowling and panels, removing and installing .............. 8-10
DDrive chain ..................................................................... 5-5
Drive chain, lubricating ................................................ 8-38
Drive chain slack .......................................................... 8-36EEngine break-in .............................................................. 6-4
Engine oil ....................................................................... 5-4
Engine oil and oil filter element .................................... 8-14
Engine, start ................................................................... 6-1
Engine stop switch ........................................................ 4-3
Engine trouble warning light .......................................... 4-2FFuel ......................................................................... 4-9, 5-4
Fuel level warning light .................................................. 4-2
Fuel tank cap ................................................................. 4-8
Fuse, replacing ............................................................ 8-46HHandlebar position, adjusting ...................................... 4-23
Handlebar switches ....................................................... 4-3
Headlight beam, adjusting ........................................... 8-49
Headlight bulb, replacing ............................................. 8-46IIdentification numbers ................................................. 11-1
Indicator light and warning lights ................................... 4-1
Instruments, lights and switches ................................... 5-7LLabel locations ............................................................... 1-1
Light switch ................................................................... 4-3
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