check engine YAMAHA YFZ450R 2016 User Guide

6-4
6erly lubricated only when the engine is run-
ning. Inadequate lubrication may damage
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.
EBU20673Engine break-inTIPFor ATVs equipped with an odometer or an hour
meter, follow the figures given in km (mi) or the
figures given in hours.
 For ATVs not equipped with an odometer or
hour meter, follow the figures given in hours. There is never a more important period in the life
of your engine than the first 320 km (200 mi) or 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 320 km (200 mi) or
20 hours. The various parts in the engine wear and
polish themselves to the correct operating clear- ances. During this period, prolonged full-throttle
operation or any condition that might result in en-
gine overheating must be avoided.
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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7-5
7Pre-operation checks
Always inspect your ATV each time you use it to
make sure the ATV is in safe operating condition.
Perform the pre-operation checks listed on page
5-1. Always follow the inspection and mainte-
nance procedures and schedules described in the
Owner’s Manual.
WARNING! Failure to inspect
the ATV before riding it or failure to maintain it
properly increases the possibility of an acci-
dent and equipment damage.
[EWB01433]
Speed limiter
For riders less experienced with this model, the
throttle lever housing is equipped with a speed
limiter. The speed limiter keeps the throttle from fully opening, even when the throttle lever is
pushed to the maximum. Turning in the adjusting
screw limits the maximum engine power available
and decreases the maximum speed of the ATV.
Turning in the adjusting screw decreases top
speed, and turning it out increases top speed.
(See page 4-5.)
Loading and accessories
WARNING
EWB00973Improper loading or towing can increase the
risk of loss of control, an overturn, or other ac-
cident. To reduce the risk of an accident:1. Adjusting screw
2. Locknut
2
1
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7-16
7
RIDING DOWNHILL
WARNING
EWB01132Going down a hill improperly could cause over-
turns or loss of control. Always follow proper
procedures for going down hills as described
in this Owner’s Manual.
 Always check the terrain carefully before you
start down any hill. 
Never operate the ATV on hills too steep for
the ATV or for your abilities. The ATV can
overturn more easily on extremely steep hills
than on level surfaces or small hills.
 Shift your weight backward and to the up
side of the hill.
 Never go down a hill at high speed.
 Avoid going down a hill at an angle that
would cause the ATV to lean sharply to one
side. Go straight down the hill where possi-
ble.
 Improper braking can cause the wheels on
the uphill side to come off the ground or
cause loss of traction. Gradually apply only
the rear brake when going downhill.
When riding your ATV downhill, shift your weight
as far to the rear and uphill side of the ATV as pos-
sible. Move back on the seat and sit with your
arms straight. Choose a low gear which will allow
the engine compression to do most of the braking
for you.
Use caution while descending a hill with loose or
slippery surfaces. Braking ability and traction may
be adversely affected by these surfaces. Improper
braking may also cause a loss of traction. Gradu-
ally apply only the rear brake.
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8-7
8
14*Drive chain roller • Check for wear and replace if necessary. √√√
15 *Chassis fasteners • Make sure that all nuts, bolts, and screws are
properly tightened. √√√√√
16 *Shock absorber as-
semblies • Check operation and correct if necessary.
• Check for oil leakage and replace if necessary.
√√√
17 *Rear suspension re-
lay arm and con-
necting arm
pivoting points • Check operation and correct if necessary.
√√√√
18 *Steering shaft • Lubricate with lithium-soap-based grease. √√√
19 *Steering system • Check operation and repair or replace if dam-
aged.
• Check toe-in and adjust 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 320U1TD62E0.book Page 7 Monday, May 18, 2015 9:20 AM

8-13
8To install the cowling
1. Place the cowling in the original position, and
then tighten the quick fasteners.
2. Install panels C, B and A.EBU29442Checking the spark plugThe spark plug is an important engine component,
which should be checked periodically, preferably
by a Yamaha dealer. Since heat and deposits will
cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
The porcelain insulator around the center elec-
trode of the spark plug should be a medium-to-
light tan (the ideal color when the vehicle is ridden
normally). If the spark plug shows a distinctly dif-
ferent color, the engine could be operating im-
properly. Do not attempt to diagnose such
problems yourself. Instead, have a Yamaha dealer
check the vehicle.
If the spark plug shows signs of electrode erosion
and excessive carbon or other deposits, it should
be replaced.
1. Quick fastener
1. Quick fastener
1
1
1
1
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8-14
8
Before installing the spark plug, the spark plug
gap should be measured with a wire thickness
gauge and, if necessary, adjusted to specification.
Clean the surface of the spark plug gasket and its
mating surface, and then wipe off any grime from
the spark plug threads.
TIPIf a torque wrench is not available when installing
the spark plug, a good estimate of the correct
torque is 1/4–1/2 turn past finger tight. However,
the spark plug should be tightened to the speci-
fied torque as soon as possible. EBU2949AEngine oil and oil filter elementThe engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter element replaced at the intervals spec-
ified in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Start the engine, warm it up until the engine oil has reached a normal temperature of 60
°C (140 °F), let it continue to idle for ten sec-
onds or more, and then turn the engine off.
Specified spark plug:
NGK/CR8E
1. Spark plug gapSpark plug gap:0.7–0.8 mm (0.028–0.031 in)
Tightening torque:Spark plug:13 Nm (1.3 m·kgf, 9.4 ft·lbf)
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8-15
8
TIPTo achieve the proper engine oil temperature for
an accurate oil level reading, the engine must have
first completely cooled down, and then warmed
up again for several minutes to normal operating
temperature. 3. Remove the engine oil tank filler cap, andwipe the engine oil dipstick off with a clean
rag.
4. Insert the dipstick into the filler hole (without screwing it in), and then remove it again to
check the oil level.TIPThe engine oil should be between the minimum
and maximum level marks.
5. If the engine oil is at or below the minimumlevel mark, add sufficient oil of the recom-
mended type through the engine oil tank filler
hole to raise it to the correct level. NOTICE:
Be sure the engine oil is at the correct lev-
el, otherwise engine damage may result.
[ECB00852]
1. Engine oil tank filler cap
2. Engine oil dipstick
3. Maximum level mark
4. Half-level mark
5. Minimum level mark1
2
3
54
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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, and then install and tighten the en-
gine oil tank filler cap.
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. 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.
14. Turn the engine off, and then check the oil level and correct it if necessary.
Tightening torques:
Crankcase engine oil drain bolt:20 Nm (2.0 m·kgf, 14 ft·lbf)
Engine oil tank drain bolt: 20 Nm (2.0 m·kgf, 14 ft·lbf)
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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8-20
8
15. 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]
EBU29861
CoolantThe coolant level should be checked before each
ride. In addition, the coolant must be changed at
the intervals specified in the periodic maintenance
and lubrication chart. Have a Yamaha dealer
change the coolant. WARNING! Never attempt
to remove the radiator cap when the engine is
hot.
[EWB02671]
EBU27945
To check the coolant level 1. Place the ATV on a level surface.
TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture. 2. Check the coolant level in the coolant reser- voir.TIPThe coolant should be between the minimum and
maximum level marks.
Tightening torque:Engine guard bolt:7 Nm (0.7 m·kgf, 5.1 ft·lbf)
1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level mark
1
2
3
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8-21
83. If the coolant is at or below the minimum level
mark, remove the coolant reservoir cap, add
coolant or distilled water to the maximum lev-
el mark, and then install the reservoir cap.
NOTICE: If coolant is not available, use
distilled water or soft tap water instead.
Do not use hard water or salt water since
they are harmful to the engine. If water has
been used instead of coolant, replace it
with coolant as soon as possible, other-
wise the cooling system will not be pro-
tected against frost and corrosion. If water
has been added to the coolant, have a
Yamaha dealer check the antifreeze con-
tent of the coolant as soon as possible,
otherwise the effectiveness of the coolant
will be reduced.
[ECB01012]
TIP The radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator. 
If the engine overheats, see page 8-52 for fur-
ther instructions.
EBU26808Cleaning the air filter elementThe air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean or, if necessary, replace
the air filter element more frequently if you are rid-
ing in unusually wet or dusty areas.TIPThere is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case.
Coolant reservoir capacity (up to the maxi-
mum level mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
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