engine YAMAHA KODIAK 450 2021 Owner's Guide

8-12
8
Select 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.
Shift to the park position and follow the instruction
on page 7-1 to start the engine. Once it has
warmed up you are ready to begin riding your
ATV. With the engine idling, shift the drive select
lever into the low-range position or the high-range
position. Apply the throttle slowly and smoothly.
The centrifugal clutch will engage and you will
start to accelerate. If the throttle is applied too
abruptly, the front wheels may lift off the ground,
resulting in a loss of directional control. Avoid
higher speeds until you are thoroughly familiar
with the operation of your ATV.
When slowing down or stopping, release the
throttle and apply the brakes smoothly and evenly.
Improper use of the brakes can cause the tires to
lose traction, reducing control and increasing the
possibility of an accident.
NOTICEECB00252Do not shift from low-range to high-range or
vice versa without coming to a complete stop.
Damage to the engine or drive train may occur. 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. To achieve maximum traction on unpaved surfac-
es, the two rear wheels turn together at the same
speed. Therefore, unless the wheel on the inside
of the turn is allowed to slip or lose some traction,
the ATV will resist turning. A special turning tech-
nique must be used to allow the ATV to make
turns quickly and easily. It is essential that this skill
be learned first at low speed.
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8-16
8
around and remount, following the procedure de-
scribed in the Owner’s Manual.
WARNING! Stall-
ing, rolling backwards or improperly
dismounting while climbing a hill could result in
ATV overturning. If you cannot control the ATV,
dismount immediately on the uphill side.
[EWB01803]RIDING DOWNHILL
WARNING
EWB01622Going 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. Apply brakes gradual-
ly. If in “2WD”, apply only the rear brake.
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. Engine compression will do most of
the braking for you. For maximum engine com-
pression braking effect, select the low-range posi-
tion and change to “4WD” before beginning to
descend the hill.
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9-1
9
EBU28789
PERIODIC MAINTENANCE AND ADJUSTMENT
EBU21677Periodic inspection, adjustment, and lubrication
will keep your vehicle in the safest and most effi-
cient condition possible. Safety is an obligation of
the vehicle owner and operator. The most impor-
tant points of vehicle inspection, adjustment, and
lubrication are explained on the following pages.
WARNING
EWB01842Failure to properly maintain the vehicle or per-
forming maintenance activities incorrectly may
increase your risk of injury or death during ser-
vice or while using the vehicle. If you are not fa-
miliar with vehicle service, have a Yamaha
dealer perform the service.
WARNING
EWB02563Turn off the engine when performing mainte-
nance unless otherwise specified.
A running engine has moving parts that can
catch on body parts or clothing and electri-
cal parts that can cause shocks or fires. 
Running the engine while servicing can lead
to eye injury, burns, fire, or carbon monoxide
poisoning - possibly leading to death. See
page 3-6 for more information about carbon
monoxide.

WARNING
EWB02691Brake discs, calipers, drums, and linings can
become very hot during use. To avoid possible
burns, let brake components cool before
touching them. The intervals given in the periodic maintenance
charts should be considered as a general guide
under normal riding conditions. However, DE-
PENDING ON THE WEATHER, TERRAIN, GEO-
GRAPHICAL LOCATION, AND INDIVIDUAL USE,
THE MAINTENANCE INTERVALS MAY NEED TO
BE SHORTENED.
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9
EBU36872Periodic maintenance chart: Emission control systemTIP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 distance 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) 240
(150) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320
1 *Fuel line • Check fuel hoses for cracks or other damage, and
replace if necessary. √√√
2Spark plug • Check condition and clean, regap, or replace if
necessary. √√√√√
3 *Va l v e s • Check valve clearance and adjust if necessary. √ √√√
4 *Crankcase breath-
er system • Check breather hose for cracks or other damage,
and replace if necessary. √√√
5 *Exhaust system • Check for leakage and replace gasket(s) if neces-
sary.
• Check for looseness and tighten all screw clamps and joints if necessary. √√√
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EBU36893Periodic 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 distance 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) 240
(150) 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 Sub air filter ele-
ment • Clean and replace if necessary.
Every 20–40 hours (more often in wet or
dusty areas)
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
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9
12*Chassis fasteners • Make sure that all nuts, bolts, and screws are
properly tightened. √√√√√
13 *Shock absorber as-
semblies • Check operation and correct if necessary.
• Check for oil leakage and replace if necessary.
√√√
14 *Stabilizer bushes • Check for cracks or other damage, and replace if
necessary. √√√
15 *Rear knuckle pivots • Lubricate with lithium-soap-based grease. √√√
16 *Steering shaft • Lubricate with lithium-soap-based grease. √√√
17 *Steering system • Check operation and repair or replace if dam-
aged.
• Check toe-in and adjust if necessary. √√√√√
18 *Engine mounts • Check for cracks or other damage, and replace if
necessary. √√√
19 *Axle boots • Check for cracks or other damage, and replace if
necessary. √√√√√
20 Engine oil • Change.
• Check ATV for oil leakage, and correct if neces-
sary. √ √√√
21 Engine oil filter car-
tridge • Replace.
√√√
22 *Engine oil strainer • Clean. √√√
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev- er comes first month136612
km (mi) 240
(150) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320UBEY60E0.book Page 7 Monday, July 27, 2020 10:46 AM

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9
5. Install the cover.
For handlebar-mounted light equipped
models: Install the handlebar-mounted
light cover.
 For non-equipped models: Install the han-
dlebar cover.
6. Install the panels.
EBU23216Checking the spark plugThe spark plug is an important engine component,
which is easy to check. Since heat and deposits
will cause any spark plug to slowly erode, the
spark plug should be removed and checked in ac-
cordance with the periodic maintenance chart. In
addition, the condition of the spark plug can reveal
the condition of the engine.
To remove the spark plug 1. Remove the spark plug cap. 2. Remove the spark plug as shown, with the
spark plug wrench included in the tool kit.
1. Spark plug cap
1. Spark plug wrench
11
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9-18
9To check the spark plug
1. Check that the porcelain insulator around the center electrode of the spark plug is a medi-
um-to-light tan (the ideal color when the ATV
is ridden normally).
TIPIf the spark plug shows a distinctly different color,
the engine could be operating improperly. Do not
attempt to diagnose such problems yourself. In-
stead, have a Yamaha dealer check the ATV. 2. Check the spark plug for electrode erosionand excessive carbon or other deposits, and
replace it if necessary.
3. Measure the spark plug gap with a wire thick- ness gauge and, if necessary, adjust the gap
to specification. To install the spark plug
1. Clean the surface of the spark plug gasket and its mating surface, and then wipe off any
grime from the spark plug threads.
2. Install the spark plug with the spark plug wrench, and then tighten it to the specified
torque.
Specified spark plug:
NGK/DR7EA
1. Spark plug gapSpark plug gap:0.6–0.7 mm (0.024–0.028 in)
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9
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. 3. Install the spark plug cap.EBU30245Engine oil and oil filter cartridgeThe engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter cartridge replaced at the intervals
specified in the periodic maintenance chart.
To check the engine oil level1. Park the ATV on a level surface.
2. Remove panel E. (See page 9-10.)
3. Check the engine oil level on a cold engine.
TIPIf the engine was started before checking the oil
level, warm up the engine, and then wait at least
ten minutes until the oil settles for an accurate
reading. 4. Remove the engine oil filler cap, and then wipe the dipstick with a clean rag.
5. Insert the dipstick into the filler hole (without screwing it in), and then remove it again to
check the oil level.
Tightening torque:
Spark plug:18 N

9-20
9
TIPThe engine oil should be between the tip of the
dipstick and the maximum level mark. 6. If the engine oil is not between the tip of thedipstick and the maximum level mark, add
sufficient oil of the recommended type to
raise it to the correct level. NOTICE: Be sure
the engine oil is at the correct level, other-
wise engine damage may result.
[ECB00852]
7. Check the filler cap O-ring for damage, and replace it if necessary.
8. Install the engine oil filler cap and the panel.
To change the engine oil (and replace the oil fil-
ter cartridge) 1. Park the ATV on a level surface.
2. Remove panel E. (See page 9-10.)
3. Start the engine, warm it up for several min- utes, and then turn it off.
4. Place an oil pan under the engine to collect the used oil.
5. Remove the engine oil filler cap, and then re- move the engine oil drain bolt and its gasket
to drain the oil from the crankcase.
1. Engine oil filler cap
2. O-ring
3. Engine oil dipstick
4. Maximum level mark
5. Tip of the engine oil dipstick
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