2018 YAMAHA YFZ450R Throttle

7-12
7To 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.
As you approach a curve, slow down and begin to
turn the handlebars in the desired direction. As
you do so, put your weight on the footrest to the
outside of the turn (opposite your desired direc-
tion) and lean your upper body into the turn. Use
the throttle to maintain an even speed through the
turn. This maneuver will let the wheel on the inside
of the turn slip slightly, allowing the ATV to make
the turn properly.
This procedure should be practiced at slow speed
many times in a large unpaved area with no obsta-
cles. If an incorrect technique is used, your ATV
may continue to go straight. If the ATV doesn’t
turn, come to a stop and then practice the proce-
dure again. If the riding surface is slippery or
loose, it may help to position more of your weight
over the front wheels by moving forward on the
seat.
1. Lean towards inside of turn.
2. Support your weight on the outer footrest.
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7-13
7
Once you have learned this technique, you should
be able to perform it at higher speeds or in tighter
curves.
Improper riding procedures such as abrupt throt-
tle changes, excessive braking, incorrect body
movements, or too much speed for the sharpness
of the turn may cause the ATV to tip. If the ATV be-
gins to tip over to the outside while negotiating a
turn, lean more to the inside. It may also be nec-
essary to gradually let off on the throttle and steer
to the outside of the turn to avoid tipping over.
Remember: Avoid higher speeds until you are
thoroughly familiar with the operation of your ATV.
CLIMBING UPHILL
WARNING
EWB01592Climbing hills improperly can cause overturns
or loss of control. Use proper riding techniques
described in this Owner’s Manual.

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.
 Always check the terrain carefully before you
start up any hill. Never climb hills with exces-
sively slippery or loose surfaces. 
Shift your weight forward.
 Never open the throttle suddenly or make
sudden gear changes. The ATV could flip
over backwards.
 Never go over the top of any hill at high
speed. An obstacle, a sharp drop, or another
vehicle or person could be on the other side
of the hill.
 Never attempt to turn the ATV around on any
hill until you have mastered the turning tech-
nique as described in the Owner’s Manual on
level ground. Be very careful when turning
on any hill.
 Avoid crossing the side of a steep hill if pos-
sible. When crossing the side of a hill, shift
your weight to the uphill side of the ATV.

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7-14
7Do not attempt to climb hills until you have mas-
tered basic maneuvers on flat ground. Always
check the terrain carefully before attempting any
hill. In all cases avoid inclines with slippery or
loose surfaces, or obstacles that might cause you
to lose control.
To climb a hill, you need traction, momentum, and
steady throttle. Travel fast enough to maintain mo-
mentum, but not so fast that you cannot react to
changes in the terrain as you climb.
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7-22
7WHAT TO DO...

If your ATV doesn’t turn when you want it to:
Bring the ATV to a stop and practice the turning
maneuvers again. Be sure you are putting your
weight on the footrest to the outside of the turn.
Position your weight over the front wheels for
better control. (See page 7-11.)
 If your ATV begins to tip while turning:
Lean more into the turn to regain balance. If
necessary, gradually let off the throttle and/or
steer to the outside of the turn. (See page 7-11.)
 If your ATV starts to slide sideways:
Steer in the direction of the slide if you have the
room. Applying the brakes or accelerating is not
recommended until you have corrected the
slide. (See page 7-20.)
 If your ATV can’t make it up a hill you are trying
to climb:
Turn the ATV around if you still have forward
speed. If not, stop, dismount on the uphill side
of the ATV and physically turn the ATV around.
If the ATV starts to slip backwards, DO NOT
USE THE REAR BRAKE – the ATV may tip over
on top of you. Dismount the ATV on the uphill
side. (See page 7-13.) 
If your ATV is traversing a sloping surface:
Be sure to ride with your weight positioned to-
wards the uphill side of the ATV to maintain
proper balance. If the ATV starts to tip, steer
down the hill (if there are no obstacles in your
way) to regain balance. If you discover that the
ATV is going to tip over, dismount on the uphill
side. (See page 7-17.)
 If your ATV encounters shallow water:
Ride slowly and carefully through slow moving
water, watching for obstacles. Be sure to let wa-
ter drain from the ATV and CHECK YOUR
BRAKES FOR PROPER OPERATION when you
come out of the water. Do not continue to ride
your ATV until you have regained adequate
braking ability. (See page 7-18.)
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8-8
8
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)
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8-25
8
17. 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. EBU30862Cleaning 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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8-27
8
WARNING
EWB02342Always let the exhaust system cool prior to
touching exhaust components.
Do not start the engine with the spark arrester
removed. Sparks or exhaust particulate can
cause eye injury, burns, or start a fire.
EBU29704Adjusting the throttle lever free playPeriodically check the throttle lever free play and
adjust if necessary.1. Slide the rubber cover back.
2. Loosen the locknut.
Tightening torque:
Tailpipe cover bolt:8 N·m (0.8 kgf·m, 5.9 lb·ft)1. Rubber cover
2. Throttle lever free play adjusting bolt
3. Locknut
4. Throttle lever free playThrottle lever free play: 2.0–4.0 mm (0.08–0.16 in)
32
4
(a)(b)
1
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8-28
83. 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
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.EBU29602BrakesReplacement of brake components requires pro-
fessional knowledge. Brake service should be
performed by a Yamaha dealer.
WARNING
EWB02572Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident.
EBU24131Checking the front and rear brake padsThe front and rear brake pads must be checked
for wear at the intervals specified in the periodic
maintenance and lubrication chart.EBU29561Front brake pads
Each brake pad is provided with wear indicator
grooves, which allow you to check the brake pad
wear without having to disassemble the brake. To
check the brake pad wear, check the wear indica-
tor grooves. If a brake pad has worn to the point
that the wear indicator grooves have almost dis-
appeared, have a Yamaha dealer replace the
brake pads as a set.
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