engine YAMAHA YFZ450R 2017 Service Manual

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8
14. Install the washer onto the air filter element
frame, and then insert the wing bolt into the
hole in the air filter element frame. NOTICE:
Be sure to install the washer with its
curved side facing outward as shown.
[ECB00454]
15. Insert the air filter element into the air filter case, and then tighten the wing bolt.
NOTICE: Make sure that the air filter ele-
ment is properly seated in the air filter
case. Never operate the engine with the air
filter element removed. Doing so would al-
low unfiltered air to enter the engine, caus-
ing rapid engine wear and possible engine
damage. Additionally, the fuel injection
system would be affected resulting in poor
engine performance and possible over-
heating.
[ECB00763]
16. Install the air filter case cover by hooking the holders onto the air filter case.
1. Air filter element seat
1
1. Washer
1
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8-25
817. Install the seat.
TIPThe air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated
more often if the ATV is operated in extremely
dusty areas. Each time the air filter element main-
tenance is performed, check the air inlet of the air
filter case for obstructions. Check the air filter
case rubber joint to the throttle body and the rub-
ber joint manifold fittings for an air-tight seal.
Tighten all fittings securely to avoid the possibility
of unfiltered air entering the engine. EBU30861Cleaning the spark arresterSelect a well-ventilated area free of combustible
materials and make sure the exhaust and muffler
are cool.
1. Remove the tailpipe cover by removing the bolts. 2. Remove the retainer by removing the bolts,
and then remove the tailpipe and gasket from
the muffler.
1. Tailpipe cover
2. Bolt2
1 2
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8
WARNING
EWB02341Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components. EBU29703Adjusting the throttle lever free playThe throttle lever free play should be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
The throttle lever free play should measure 2.0–4.0
mm (0.08–0.16 in) as shown. Periodically check
the throttle lever free play and, if necessary, adjust
it as follows.1. Slide the rubber cover back.
2. Loosen the locknut. 3. To increase the throttle lever free play, turn
the throttle lever free play adjusting bolt in di-
rection (a). To decrease the throttle lever free
play, turn the adjusting bolt in direction (b).
4. Tighten the locknut.
5. Slide the rubber cover to its original position.
EBU24061Valve clearanceThe valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
Tightening torque:
Tailpipe cover bolt:8 N·m (0.8 kgf·m, 5.8 lb·ft)1. Rubber cover
2. Throttle lever free play adjusting bolt
3. Locknut
4. Throttle lever free play
32
4
(a)(b)
1
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8
TIPA rod can be obtained at a Yamaha dealer to make
this adjustment. 4. Shift the transmission into neutral.
5. To tighten the drive chain, push the ATVbackward. To loosen the drive chain, push
the ATV forward. NOTICE: Improper drive
chain slack will overload the engine as well
as other vital parts of the ATV and can lead
to drive chain slippage or breakage. To prevent this from occurring, keep the drive
chain slack within the specified limits.
[ECB00543]
6. Pull the rod out, and then tighten the rear axle
pinch bolts to the specified torque in the or-
der shown.
1. Rear wheel axle pinch bolt
2. Rod
3. Drive chain tensioner
4. Hole
3
4
2 11
Tightening torque:
Rear axle pinch bolt:21 N·m (2.1 kgf·m, 15 lb·ft)
3 1 2
4
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EBU24883Lubricating the drive chainThe drive chain must be cleaned and lubricated at
the intervals specified in the periodic maintenance
and lubrication chart, otherwise it will quickly wear
out, especially when riding in dusty or wet areas.
Service the drive chain as follows.NOTICEECB00562The drive chain must be lubricated after wash-
ing the ATV or riding in the rain or wet areas. 1. Clean the drive chain with kerosene and asmall soft brush. NOTICE: To prevent dam-
aging the O-rings, do not clean the drive
chain with steam cleaners, high-pressure
washers or inappropriate solvents.
[ECB00572]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a special O-ring chain lubricant. NOTICE: Do
not use engine oil or any other lubricants
for the drive chain, as they may contain
substances that could damage the O-
rings.
[ECB00582]
EBU24905
Checking and lubricating the cablesThe operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-1. O-rings
1
1
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8
EBU27695Troubleshooting chartsStarting problems or poor engine performance
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.There is no fuel.
Check the battery.
Supply fuel.
The engine does not start.
Check the battery.
Operate the electric starter.4. Compression
There is compression.
There is no compression.
The engine does not start.
Have a Yamaha dealer check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug. Have a Yamaha dealer check the ATV.
The engine does not start.
Check the compression.
DryWet
Operate the electric starter.
Have a Yamaha dealer check the ATV.
The engine does not start.
Check the ignition.
Operate the electric starter.2. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and have a Yamaha dealer charge
the battery if necessary.
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8Engine overheating
WARNING
EWB02291Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap. TIPIf coolant is not available, tap water can be temporarily used instead, provided that it is changed to the
recommended coolant as soon as possible. Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer check
and repair the cooling system.Add coolant. (See TIP.)
Start the engine. If the engine overheats again, have a
Yamaha dealer check and repair the cooling system.
There is
leakage.
There is
no leakage.
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EBU25861
CLEANING AND STORAGE
EBU25903CleaningFrequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.1. Before cleaning the ATV: a. Block off the end of the exhaust pipe toprevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps are properly installed.
2. If the engine case is excessively greasy, apply degreaser with a paint brush. Do not apply
degreaser to the chain, sprockets or wheel
axles.
3. Rinse the dirt and degreaser off with a garden hose. Use only enough pressure to do the
job. WARNING! Wet brakes may have re-
duced stopping ability, increasing the
chance of an accident. Test the brakes af-
ter washing. Apply the brakes several
times at slow speeds to let friction dry out
the linings.
[EWB02312]
NOTICE: Excessive wa- ter pressure may cause water seepage
and deterioration of wheel bearings,
brakes, transmission seals and electrical
devices. Many expensive repair bills have
resulted from improper high-pressure de-
tergent applications such as those avail-
able in coin-operated car washers.
[ECB00712]
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or
bottle brush is handy for hard-to-reach pla-
ces.
5. Rinse the ATV off immediately with clean wa- ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Dry the chain and lubricate it to prevent it from rusting.
7. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
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9abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.
EBU27262StorageShort-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.
NOTICE: Storing the ATV in a poorly ven-
tilated room or covering it with a tarp while it is
still wet, will allow water and humidity to seep
in and cause rust. To prevent corrosion, avoid
damp cellars, stables (because of the presence
of ammonia) and areas where strong chemi-
cals are stored.
[ECB00722]
Long-term
Before storing your ATV for several months: 1. Follow all the instructions in the “Cleaning” section of this chapter.
2. Fill up the fuel tank and add fuel stabilizer (if available) to prevent the fuel from deteriorat-
ing. 3. Perform the following steps to protect the cyl-
inder, piston rings, etc. from corrosion.a. Remove the spark plug cap and spark plug.
b. Pour a teaspoonful of engine oil into the spark plug bore.
c. Install the spark plug cap onto the spark plug, and then place the spark plug on the
cylinder head so that the electrodes are
grounded. (This will limit sparking during
the next step.)
d. Turn the engine over several times with the starter. (This will coat the cylinder wall
with oil.)
e. Remove the spark plug cap from the spark plug, and then install the spark plug and
the spark plug cap.
4. Lubricate all control cables and the pivoting points of all levers and pedals.
5. Check and, if necessary, correct the tire air pressure, and then block up the ATV so that
all of its wheels are off the ground. Alterna-
Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1
oz of stabilizer to each gallon of fuel)UBW260E0.book Page 2 Thursday, May 12, 2016 2:28 PM

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EBU25962
SPECIFICATIONS
Dimensions:Overall length:1795 mm (70.7 in)
Overall width: 1240 mm (48.8 in)
Overall height:
1065 mm (41.9 in)
Seat height: 810 mm (31.9 in)
Wheelbase: 1270 mm (50.0 in)
Ground clearance:
235 mm (9.3 in)
Minimum turning radius: 3600 mm (142 in)Weight:Curb weight:
184.0 kg (406 lb)Noise and vibration level:Noise level (77/311/EEC):85.9 dB(A) at 3750 r/min (YFZ45YSSH,
YFZ45YSXH_EUR/FRA/GBR)
Uncertainty of measurement: 3.0 dB(A) (YFZ45YSSH, YFZ45YSXH_EUR/FRA/GBR)
A-weighted sound power level:
99.0 dB(A) at 3750 r/min (YFZ45YSSH,
YFZ45YSXH_EUR/FRA/GBR) Uncertainty of measurement:
3.0 dB(A) (YFZ45YSSH, YFZ45YSXH_EUR/FRA/GBR)
Vibration on seat (EN1032, ISO5008): Will not exceed 0.5 m/s² (YFZ45YSSH,
YFZ45YSXH_EUR/FRA/GBR)
Uncertainty of measurement: 0.1 m/s² (YFZ45YSSH, YFZ45YSXH_EUR/FRA/GBR)
Vibration on handle (EN1032, ISO5008): Will not exceed 2.5 m/s² (YFZ45YSSH,
YFZ45YSXH_EUR/FRA/GBR)
Uncertainty of measurement: 0.8 m/s² (YFZ45YSSH, YFZ45YSXH_EUR/FRA/GBR)
Engine:Engine type:Liquid cooled 4-stroke, DOHC
Cylinder arrangement: Single cylinder
Displacement:
449 cm³
Bore × stroke:
95.0 × 63.4 mm (3.74 × 2.50 in)
Compression ratio: 11.8 : 1
Starting system:
Electric starter
Lubrication system: Dry sump
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