check engine YAMAHA GRIZZLY 450 2010 User Guide

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.
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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.
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8-3
8
EBU21743Periodic maintenance chart for the emission control system TIP
For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.
For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance inter-
vals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance
intervals should be followed.
Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills.NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320
1*Fuel lineCheck fuel hoses for cracks or other damage, and
replace if necessary.√√√
2 Spark plugCheck condition and clean, regap, or replace if
necessary.√√√√√
3*ValvesCheck valve clearance and adjust if necessary.√ √√√
4*CarburetorCheck starter (choke) operation and correct if nec-
essary.
Check engine idling speed and adjust if neces-
sary.√√√√
5*Crankcase breather
systemCheck breather hose for cracks or other damage,
and replace if necessary.√√√
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8-7
8
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.√√√
20*Engine oil strainerClean.√√√
21 Differential gear oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√√
22 Final gear oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√√√
23 Cooling systemCheck coolant level and ATV for coolant leakage,
and correct if necessary.√√√√√
Replace coolant. Every 2 years
24*Moving parts and
cablesLubricate.√√√√
25*Drive select lever
safety system cableCheck operation and adjust or replace if neces-
sary.√√√ 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 320U37S61E0.book Page 7 Tuesday, June 2, 2009 10:33 AM

8-14
8To install the panel
Place the panel in the original position and install
the bolts.
Panel F
To remove the panelPull outward on the areas shown.
To install the panelPlace the panel in its original position.
EBU23223Checking 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 panel A. (See page 8-9.)
2. Remove the spark plug cap.
1. Panel FU37S61E0.book Page 14 Tuesday, June 2, 2009 10:33 AM

8-15
8 3. 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).
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.
1. Spark plug cap
1. Spark plug wrench
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8-17
8
EBU23328Engine 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. Remove panel F. (See page 8-9.)
3. 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 ten minutes until the oil set-
tles for an accurate reading.4. Remove the engine oil filler cap, and then
wipe the engine oil dipstick off 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.
TIPThe engine oil should be between the minimum
and maximum level marks.1. Engine oil filler cap
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8-21
8 12. Refill with the specified amount of the recom-
mended engine oil, and then install and tight-
en the engine oil filler cap.
TIPBe sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.NOTICEECB00300
In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
with a diesel specification of “CD” or oils of
a higher quality than specified. In addition,
do not use oils labeled “ENERGY CONSERV-
ING II” or higher.

Make sure that no foreign material enters the
crankcase.13. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
14. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
15. Install panel F.EBU28573Final gear oil The final gear case must be checked for oil leak-
age before each ride. If any leakage is found, have
a Yamaha dealer check and repair the ATV. In ad-
dition, the final gear oil level must be checked and
the oil changed as follows at the intervals specified
in the periodic maintenance and lubrication chart.
To check the final gear oil level
1. Place the ATV on a level surface.TIPThe final gear oil level must be checked when the
engine is cold.
Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter cartridge replacement:
2.30 L (2.43 US qt, 2.02 Imp.qt)
With oil filter cartridge replacement:
2.40 L (2.54 US qt, 2.11 Imp.qt)
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8-22
82. Remove the final gear oil filler bolt, and then
check the oil level in the final gear case. The
oil level should be at the brim of the filler hole.
3. If the oil is below the brim of the filler hole, add
sufficient oil of the recommended type to raise
it to the correct level.
4. Install the oil filler bolt, and then tighten it to the
specified torque.To change the final gear oil
1. Place the ATV on a level surface.
2. Remove the engine guard and the final gear
case guard by removing the bolts.
3. Place an oil pan under the final gear case to
collect the used oil.
4. Remove the final gear oil filler bolt and the fi-
nal gear oil drain bolt to drain the oil from the
final gear case.
1. Final gear oil filler bolt
2. Correct oil level
3. Final gear oilTightening torque:
Final gear oil filler bolt:
24 Nm (2.4 m·kgf, 17 ft·lbf)
1. Engine guard
2. Final gear case guard
3. Bolt
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8-24
88. Check the final gear case for oil leakage. If oil
is leaking, check for the cause.
9. Install the engine guard and the final gear
case guard by installing the bolts, and then
tightening them to the specified torques.
EBU23423Differential gear oil The differential gear case must be checked for oil
leakage before each ride. If any leakage is found,
have a Yamaha dealer check and repair the ATV.
In addition, the differential gear oil level must be
checked and the oil changed as follows at the in-
tervals specified in the periodic maintenance and
lubrication chart.To check the differential gear oil level
1. Place the ATV on a level surface.
TIPThe differential gear oil level must be checked
when the engine is cold.2. Remove the differential gear oil filler bolt, and
then check the oil level in the differential gear
case. The oil level should be at the brim of the
filler hole. Tightening torque:
Final gear oil filler bolt:
24 Nm (2.4 m·kgf, 17 ft·lbf)
Tightening torques:
Engine guard bolt:
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
Final gear case guard bolt:
7 Nm (0.7 m·kgf, 5.1 ft·lbf)1. Differential gear oil
2. Differential gear oil filler bolt
3. Correct oil level
U37S61E0.book Page 24 Tuesday, June 2, 2009 10:33 AM