engine YAMAHA GRIZZLY 550 2015 Owner's Guide

7-6
7
fully opening, even when the throttle lever is
pushed to the maximum. Turning in the adjusting
screw limits the maximum engine power available
and decreases the maximum speed of the ATV.
Turning in the adjusting screw decreases top
speed, and turning it out increases top speed.
(See page 4-13.)
Loading and accessories
WARNING
EWB01463Improper 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 “MAXIMUM LOADING
LIMIT” in this section or vehicle 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 screw
1
U2LB61E0.book Page 6 Friday, February 21, 2014 3:03 PM

7-8
7
an overturn. Never attempt stunts, such as
wheelies or jumps. Don’t try to show off.
[EWB01482]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
designed for use on this ATV and should be in-
stalled 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.
[EWB01492]
Exhaust system
WARNING
EWB01502 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 operating in areas where combustible mate-
rials may have collected. Do not idle or park the
vehicle in long dry grass or other dry ground cov-
er.
U2LB61E0.book Page 8 Friday, February 21, 2014 3:03 PM

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
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.
U2LB61E0.book Page 12 Friday, February 21, 2014 3:03 PM

7-16
7
straight uphill. Turn the ATV around and 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 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 cau-
se loss of traction. Apply brakes gradually. 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.
U2LB61E0.book Page 16 Friday, February 21, 2014 3:03 PM

8-1
8
EBU28784
PERIODIC MAINTENANCE AND ADJUSTMENT
EBU21675Periodic 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/operator. The most important
points of vehicle inspection, adjustment, and lu-
brication 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 2-6 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.
U2LB61E0.book Page 1 Friday, February 21, 2014 3:03 PM

8-7
8
11*Shock absorber as-
semblies • Check operation and correct if necessary.
• Check for oil leakage and replace if necessary.
√√√
12 *Stabilizer bushes • Check for cracks or other damage, and replace if
necessary. √√√
13 *Rear knuckle pivots • Lubricate with lithium-soap-based grease. √√√
14 *Steering shaft • Lubricate with lithium-soap-based grease. √√√
15 *Steering system • Check operation and repair or replace if dam-
aged.
• Check toe-in and adjust if necessary. √√√√√
16 *Engine mount • Check for cracks or other damage, and replace if
necessary. √√√
17 *Axle boots • Check for cracks or other damage, and replace if
necessary. √√√√√
18 Engine oil • Change.
• Check ATV for oil leakage, and correct if neces-
sary. √ √√√
19 Engine oil filter car-
tridge • Replace.
√√√
20 Differential gear oil • Change.
• Check ATV for oil leakage, and correct if neces-
sary. √√
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 320U2LB61E0.book Page 7 Friday, February 21, 2014 3:03 PM

8-20
8
EBU23214Checking 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 and lubri-
cation chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
To remove the spark plug1. Remove the spark plug cap. 2. Remove the spark plug as shown, with the
spark plug wrench included in the owner’s
tool kit.
To 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).1. Spark plug cap1
1. Spark plug wrench
U2LB61E0.book Page 20 Friday, February 21, 2014 3:03 PM

8-21
8
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 plug1. 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/LMAR6A-9
1. Spark plug gapSpark plug gap:0.8–0.9 mm (0.031–0.035 in)
U2LB61E0.book Page 21 Friday, February 21, 2014 3:03 PM

8-22
8
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.EBU27468Engine 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 and lubrica-
tion chart.
To check the engine oil level1. Place the ATV on a level surface.
2. Check the engine oil level on a cold engine.
TIPIf the engine was started before checking the oil
level, be sure to warm up the engine sufficiently,
and then wait at least 10 minutes until the oil set-
tles for an accurate reading. 3. Remove the access cover by turning it coun- terclockwise.
4. Remove the engine oil dipstick, and then wipe it off with a clean rag.
Tightening torque:
Spark plug:13 Nm (1.3 m·kgf, 9.4 ft·lbf)1. Access cover
U2LB61E0.book Page 22 Friday, February 21, 2014 3:03 PM

8-23
8
5. Insert the dipstick completely into the oil filler
hole, and then remove it again to check the oil
level.
TIPThe engine oil should be between the minimum
and maximum level marks.
6. If the engine oil is at or below the minimumlevel mark, add sufficient oil of the recom-
mended type to raise it to the correct level.
NOTICE: Be sure the engine oil is at the
correct level, otherwise engine damage
may result.
[ECB00852]
7. Insert the dipstick completely into the oil filler hole.
8. Install the access cover by turning it clock- wise.
1. Engine oil dipstick
1. Maximum level mark
2. Minimum level mark
U2LB61E0.book Page 23 Friday, February 21, 2014 3:03 PM