2021 YAMAHA YFZ450R cooling

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EBU19203
PRE-OPERATION CHECKS
EBU19227Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always
follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWB00482Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equip-
ment damage. Do not operate the vehicle if you find any problem. If a problem cannot be corrected
by the procedures provided in this manual, have the vehicle inspected by a Yamaha dealer. Before using this vehicle, check the following points:
ITEMROUTINE PAGE
Fuel • Check fuel level in fuel tank,
and add recommended fuel if neces-
sary.
• Check fuel line for leakage. Correct if necessary. 5-9, 6-4
Engine oil • Check oil level in engine oil
tank, and add recommended oil to
specified level if necessary.
• Check ATV for oil leakage. Correct if necessary. 6-4, 9-14
Coolant • Check coolant level in reservoir, and add recommended coolant to
specified level if necessary.
• Check cooling system for leakage. Correct if necessary. 6-4, 9-20
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9-7
9
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 320UBKD60E0.book Page 7 Wednesday, November 18, 2020 8:39 AM

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stead of coolant, replace it with coolant as
soon as possible, otherwise the cooling
system will not be protected against frost
and corrosion. If water has been added to
the coolant, have a Yamaha dealer check
the antifreeze content of the coolant as
soon as possible, otherwise the effective-
ness of the coolant will be reduced.
[ECB01012]
EBU29863
Changing the coolant
The coolant must be changed at the intervals
specified in the periodic maintenance chart. Have
a Yamaha dealer change the coolant. WARNING!
Never attempt to remove the radiator cap
when the engine is hot.
[EWB04300]
EBU2680B
Cleaning the air filter elementThe air filter element should be cleaned at the in-
tervals specified in the periodic maintenance
chart. Clean or, if necessary, replace the air filter
element more frequently if you are riding in unusu-
ally 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. 1. Park the ATV on a level surface.
2. Remove the seat. (See page 5-10.)
3. Remove the air filter case cover by unhooking the holders.1. Air filter case check hose
1
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9-53
9Engine 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. TIP
Tap water can be used in an emergency. Change to the recommended coolant as soon as possible.
 The engine will tend to overheat if the radiator is caked with mud, or if the ATV is overloaded. 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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EBU25964
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: 3.6 m (11.81 ft)
Maximum water depth: 35 cm (14 in)Weight:Curb weight:184.0 kg (406 lb)Loading:Maximum load:
100.0 kg (220 lb)
(Total weight of rider, cargo, accessories, and tongue)Noise and vibration level:Noise level (77/311/EEC):85.9 dB(A) at 3750 r/min Uncertainty of measurement:
3.0 dB(A)
A-weighted sound power level: 99.0 dB(A) at 3750 r/min
Uncertainty of measurement: 3.0 dB(A)
Vibration on seat (EN1032, ISO5008):
Will not exceed 0.5 m/s²
Uncertainty of measurement: 0.1 m/s²
Vibration on handle (EN1032, ISO5008): 2.9 m/s²
Uncertainty of measurement:
0.8 m/s²
Engine:Combustion cycle:4-stroke
Cooling system:
Liquid cooled
Valve train: DOHC
Number of cylinders: Single cylinder
Displacement:
449 cm³
Bore × stroke:
95.0 × 63.4 mm (3.74 × 2.50 in)
Compression ratio: 11.8 : 1
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