YAMAHA YFZ450R 2021 Owners Manual

9-6
9
5*Brake hoses • Check for cracks or other damage, and replace if
necessary. √√√√
• Replace. Every 4 years
6 *Brake fluid • Change. Every 2 years
7 *Parking brake • Check operation and adjust if necessary. √√√√√
8 *Wheels • Check runout and for damage, and replace if nec-
essary. √ √√√
9 *Tires • Check tread depth and for damage, and replace if
necessary.
• Check air pressure and balance, and correct if necessary. √ √√√
10 *Wheel hub bearings • Check for looseness or damage, and replace if
necessary. √ √√√
11 *Swingarm pivots • Check operation and for excessive play, and re-
place bearings if necessary.
• Lubricate with lithium-soap-based grease. √√√
12 *Upper and lower
arm pivots • Lubricate with lithium-soap-based grease.
√√√
13 Drive chain • Check chain slack and adjust if necessary.
• Check rear wheel alignment and correct if neces-
sary.
• Clean and lubricate. √√√√√
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
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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

9-8
9
EBU29431TIPSome maintenance items need more frequent service if you are riding in unusually wet, dusty, sandy or
muddy areas, or at full-throttle.
 Replace the fuel hose every five years and if cracked or damaged.
 Hydraulic brake service
• Regularly check and, if necessary, correct the brake fluid level.
• Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.23 *Moving parts and
cables •Lubricate.
√√√√
24 *Throttle lever • Check operation.
• Check throttle lever free play, and adjust if neces-
sary.
• Lubricate cable and lever housing. √√√√√
25 *Front and rear
brake switches • Check operation and correct if necessary.
√√√√√
26 *Lights and switches • Check operation and correct if necessary.
• Adjust headlight beams. √√√√√
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 8 Wednesday, November 18, 2020 8:39 AM

9-9
9• Replace the brake hoses every four years and if cracked or damaged.
UBKD60E0.book Page 9 Wednesday, November 18, 2020 8:39 AM

9-10
9
EBU30131Removing and installing the cowling
and panelsThe cowling and panels shown need to be re-
moved to perform some of the maintenance jobs
described in this chapter. Refer to this section
each time a cowling or panel needs to be removed
and installed.
EBU29596Panel A
To remove the panel1. Remove the seat. (See page 5-10.)
2. Remove the fuel tank cap by turning it coun-terclockwise. (See page 5-8.) NOTICE: Make
sure that no foreign material enters the
fuel tank.
[ECB01052]
3. Loosen the quick fasteners.
1. Panel A
2. Panel B
3. Cowling
1
2
3
1. Panel C
1
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9-11
94. Remove the quick fasteners, and then slide
the panel backward and pull upward. 5. Install the fuel tank cap by turning it clock-
wise.
To install the panel
1. Remove the fuel tank cap by turning it coun- terclockwise.
2. Place the panel in the original position, and then install the quick fasteners. NOTICE:
When installing the panel, be sure not to
pinch the cables or wires.
[ECB00382]
3. Tighten the quick fasteners.
4. Install the fuel tank cap by turning it clock- wise.
5. Install the seat.
1. Quick fastener
1. Quick fastener
1 1
1
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9-12
9
Panels B and C
To remove a panel
1. Remove panel A.
2. Pull the panel off.
To install a panel1. Place the panel in the original position. 2. Install panel A.
Cowling
To remove the cowling
1. Remove panels A, B and C.
2. Loosen the quick fasteners, and then take the cowling off.
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9-13
9To install the cowling
1. Place the cowling in the original position, and
then tighten the quick fasteners.
2. Install panels C, B and A.EBU29443Checking 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 chart. In ad-
dition, 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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9
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. EBU2949EEngine 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 chart.
To check the engine oil level
1. Park 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 N·m (1.3 kgf·m, 9.6 lb·ft)
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9-15
9
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. O-ring
3. Engine oil dipstick
4. Maximum level mark
5. Half-level mark
6. Minimum level mark12
3
4
65
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