2010 YAMAHA GRIZZLY 450 engine

6-3
6
EBU20291Starting a warm engine Follow the same procedure as for starting a cold
engine, with the exception that the starter (choke)
is not required when the engine is warm. Instead,
start the engine with the throttle slightly open.EBU20441Operating the drive select lever and
driving in reverse NOTICEECB00170Before shifting, stop the ATV, otherwise the
transmission may be damaged.Shifting: Neutral to High-range and High-range
to Low-range
1. Bring the ATV to a complete stop.
2. Apply the brake pedal, and then shift by mov-
ing the drive select lever along the shift guide.TIPMake sure that the drive select lever is completely
shifted into position.
3. Release the brake pedal, and then open the
throttle lever gradually.
Shifting: Neutral to Reverse and Reverse to
Park
WARNING
EWB00720Improper operation in reverse could make you
hit an obstacle or even a person behind you,
resulting in serious injury. When you shift into1. Drive select lever
2. L (Low-range)
3. H (High-range)
4. N (Neutral)
5. R (Reverse)
6. P (Park)
L2H3N4R5P6
U37S61E0.book Page 3 Tuesday, June 2, 2009 10:33 AM

6-5
64. Check behind for people or obstacles, and
then release the brake pedal.
5. Open the throttle lever gradually and continue
to watch to the rear while backing.
EBU20682Engine break-in TIP
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 operate 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 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.
NOTICEECB00220If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV.EBU20690Parking When parking the ATV, stop the engine, shift the
drive select lever into the park position, and then
turn the fuel cock to the “OFF” position.
U37S61E0.book Page 5 Tuesday, June 2, 2009 10:33 AM

6-6
6
EBU20820Parking on a slope
WARNING
EWB00860Avoid parking on hills or other inclines. Park-
ing on a hill or other incline could cause the
ATV to roll out of control, increasing the
chance of an accident. If you must park on an
incline, place the ATV transversely across the
incline, stop the engine, shift the drive select
lever to the park position, and then block the
front and rear wheels with rocks or other ob-
jects.
Do not park the ATV at all on hills that are so
steep you could not walk up them easily.1. Bring the ATV to a stop by applying the
brakes.
2. Stop the engine.
3. With the brake pedal applied, shift the drive
select lever to the park position.
EBU20910Accessories and loading EBU20921Genuine Yamaha Accessories
Choosing accessories for your ATV is an important
decision. Genuine Yamaha Accessories, which
are available only from a Yamaha dealer, have
been designed, tested, and approved by Yamaha
for use on your ATV. Many companies with no con-
nection to Yamaha manufacture parts and acces-
sories or offer other modifications for Yamaha
vehicles. Yamaha is not in a position to test the
products that these aftermarket companies pro-
duce. Therefore, Yamaha can neither endorse nor
recommend the use of accessories not sold by
U37S61E0.book Page 6 Tuesday, June 2, 2009 10:33 AM

7-3
7Riding your ATV requires skills acquired
through practice over a period of time.
Do not attempt to operate at maximum perfor-
mance until you are totally familiar with the ATV’s
handling and performance characteristics. Take
the time to learn the basic techniques well before
attempting more difficult maneuvers. Become fa-
miliar with this ATV at slow speeds first, even if you
are an experienced operator.
Not recommended for children under 16 years
of age.
WARNING
EWB01390A child under 16 should never operate an ATV
with engine size greater than 90 cc. Use by chil-
dren of ATVs that are not recommended for
their age can lead to severe injury or death of
the child.
This ATV is designed to carry the operator and
cargo only – passengers prohibited.
The long seat is to allow the operator to shift posi-
tion as needed during operation. It is not for carry-
ing passengers. WARNING! Never carry a
passenger. Carrying a passenger on this ATV
greatly reduces your ability to balance and
control this ATV. You could have an accident,
resulting in severe injury or death to you
and/or your passenger.
[EWB01401]
U37S61E0.book Page 3 Tuesday, June 2, 2009 10:33 AM

7-6
7 opening, even when the throttle lever is pushed to
the maximum. Turning in the adjusting screw limits
the maximum engine power available and de-
creases the maximum speed of the ATV. Turning
in the adjusting screw decreases top speed, and
turning it out increases top speed. (See page
4-11.)
Loading and accessories
WARNING
EWB01461Improper loading or towing can increase the
risk of loss of control, an overturn, or other ac-
cident. To reduce the risk of an accident:

Do not exceed the maximum loading limits
for the vehicle (see box in this section or ve-
hicle labeling).
Keep weight on racks centered side to side,
and as low as possible. Be sure cargo is se-
cured – a loose load could change handling
unexpectedly.
Make sure the load does not interfere with
your control or ability to see where you are
going.
Tie down cargo in the trailer securely. Make
sure cargo in the trailer cannot move around.
A shifting load can cause an accident.
Reduce speed and allow more room to stop.
A heavier vehicle takes longer to stop.
Avoid hills and rough terrain. Choose terrain
carefully. Use extreme caution when towing
or carrying a load on inclines.
Turn gradually and go slowly.Take extra precautions when driving with a load or
trailer. Follow these instructions and always use
common sense and good judgment when carrying
cargo or towing a trailer.
1. Adjusting screwU37S61E0.book Page 6 Tuesday, June 2, 2009 10:33 AM

7-8
7 an overturn. Never attempt stunts, such as
wheelies or jumps. Don’t try to show off.
[EWB01481]Modifications and accessories
Never modify this ATV through improper installa-
tion or use of accessories or other modification. All
parts and accessories added to this ATV should be
genuine Yamaha or equivalent components de-
signed for use on this ATV and should be installed
and used according to instructions. If you have
questions, consult an authorized ATV dealer.
WARNING! Operating this ATV with improper
modifications may cause changes in handling
which in some situations could lead to an acci-
dent.
[EWB01491]
Exhaust system
WARNING
EWB01501
Dry grass or brush or other combustible ma-
terial accumulated around the engine area
could catch fire. Do not operate, idle, or park
the ATV in dry grass or other dry ground cov-
er. Keep the engine area free of dry grass,
brush, or other combustible material.
Someone touching the exhaust system dur-
ing or after operation could be burned. Do
not touch the hot exhaust system. Do not
park the ATV in a place where others might
be likely to touch it.The muffler and other engine parts become ex-
tremely hot during operation and remain hot after
the engine has stopped. To reduce the risk of fire
during operation or after leaving the ATV, do not let
brush, grass and other materials collect under the
vehicle, near the muffler or exhaust pipe, or next to
other hot parts. Check under the vehicle after op-
erating in areas where combustible materials may
have collected. Do not idle or park the vehicle in
long dry grass or other dry ground cover.
U37S61E0.book Page 8 Tuesday, June 2, 2009 10:33 AM

7-12
7 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 6-1 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 posi-
tion. 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 throt-
tle and apply the brakes smoothly and evenly. Im-
proper use of the brakes can cause the tires to lose
traction, reducing control and increasing the possi-
bility of an accident.
NOTICEECB00251Do 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
EWB01771Always 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.
U37S61E0.book Page 12 Tuesday, June 2, 2009 10:33 AM

7-16
7 remount, following the procedure described in the
Owner’s Manual. WARNING! Stalling, rolling
backwards or improperly dismounting while
climbing a hill could result in ATV overturning.
If you cannot control the ATV, dismount imme-
diately on the uphill side.
[EWB01802]
RIDING DOWNHILL
WARNING
EWB01621Going down a hill improperly could cause
overturns or loss of control. Always follow
proper procedures for going down hills as de-
scribed 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 compres-
sion braking effect, select the low-range position
and change to “4WD” before beginning to descend
the hill.
U37S61E0.book Page 16 Tuesday, June 2, 2009 10:33 AM