2011 YAMAHA GRIZZLY 550 engine

7-16
7 uphill. Turn the ATV around and remount, following
the procedure described in the Owner’s Manual.
WARNING! Stalling, rolling backwards or im-
properly dismounting while climbing a hill
could result in ATV overturning. If you cannot
control the ATV, dismount immediately 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.
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8-1
8
EBU28783
PERIODIC MAINTENANCE AND ADJUSTMENT
EBU21672Periodic 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 lubri-
cation are explained on the following pages.
WARNING
EWB01841Failure 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
EWB02561Turn 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 2-1 for more information about carbon
monoxide.
WARNING
EWB02690Brake 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
and lubrication chart should be considered as a
general guide under normal riding conditions.
However, DEPENDING ON THE WEATHER,
TERRAIN, GEOGRAPHICAL LOCATION, AND
INDIVIDUAL USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORTENED.
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8-7
8
10*Chassis fastenersMake sure that all nuts, bolts, and screws are
properly tightened.√√√√√
11*Shock absorber as-
sembliesCheck operation and correct if necessary.
Check for oil leakage and replace if necessary.√√√
12*Stabilizer bushesCheck for cracks or other damage, and replace if
necessary.√√√
13*Rear knuckle pivotsLubricate with lithium-soap-based grease.√√√
14*Steering shaftLubricate with lithium-soap-based grease.√√√
15*Steering systemCheck operation and repair or replace if damaged.
Check toe-in and adjust if necessary.√√√√√
16*Engine mountCheck for cracks or other damage, and replace if
necessary.√√√
17*Axle bootsCheck for cracks or other damage, and replace if
necessary.√√√√√
18 Engine oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√ √√√
19Engine oil filter car-
tridgeReplace.√√√ NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320U28P62E0.book Page 7 Thursday, March 11, 2010 3:25 PM

8-22
8
EBU23213Checking the spark plug The 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 accor-
dance with the periodic maintenance and lubrica-
tion 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 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
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8-23
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 erosion
and 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/LMAR6A-9
1. Spark plug gapSpark plug gap:
0.8–0.9 mm (0.031–0.035 in)
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8-24
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 specified
torque as soon as possible.3. Install the spark plug cap.EBU27466Engine oil and oil filter cartridge The 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 spec-
ified in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. 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 settles
for an accurate reading.3. Remove panel F. (See page 8-10.)
4. Remove the engine oil dipstick, and then wipe
it off with a clean rag.
5. Insert the dipstick completely into the oil filler
hole, and then remove it again to check the oil
level. Tightening torque:
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)1. Engine oil dipstick
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8
TIPThe engine oil should be between the minimum
and maximum level marks.6. If the engine oil is at or below the minimum
level 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.
[ECB00851]
7. Insert the dipstick completely into the oil filler
hole.
8. Install the panel.To change the engine oil (with or without oil fil-
ter cartridge replacement)
1. Place the ATV on a level surface.
2. Remove panel F. (See page 8-10.)
3. Place an oil pan under the engine to collect
the used oil.
4. Remove the dipstick, and then remove the en-
gine oil drain bolt and its gasket to drain the oil
from the crankcase.
TIPSkip steps 5–9 if the oil filter cartridge is not being
replaced.
1. Maximum level mark
2. Minimum level mark
1. Engine oil drain bolt
2. Gasket
12
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8-26
85. Remove panel G. (See page 8-10.)
6. Remove the oil filter cartridge with an oil filter
wrench.
TIPAn oil filter wrench is available at a nearby Yamaha
dealer.7. Apply a thin coat of engine oil to the O-ring of
the new oil filter cartridge.
TIPMake sure that the O-ring is properly seated.8. Install the new oil filter cartridge with an oil fil-
ter wrench, and then tighten it to the specified
torque with a torque wrench.
1. Oil filter cartridge
2. Oil filter wrench
1. O-ring
U28P62E0.book Page 26 Thursday, March 11, 2010 3:25 PM