engine YAMAHA GRIZZLY 125 2010 Owner's Guide

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2. Check the spark plug for electrode erosion
and excessive carbon or other deposits, and
replace it if necessary.
To install the spark plug
1. Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.2. Clean the surface of the spark plug gasket
and its mating surface, and then wipe off any
grime from the spark plug threads.
3. Install the spark plug with the spark plug
wrench, and then tighten it to the specified
torque.TIP

If a torque wrench is not available when installing
a 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.
4. Install the spark plug cap.
EBU23266
Engine oil
The engine oil level should be checked before
each ride. In addition, the oil must be changed at
the intervals specified in the periodic maintenance
and lubrication chart. Specified spark plug:
NGK/CR7HSA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1. Spark plug gap
Tightening torque:
Spark plug:
12.5 Nm (1.3 m·kgf, 9.0 ft·lbf)

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To check the engine oil level
1. Place the ATV on a level surface.
2. Check the engine oil level on a cold engine.
TIP

If 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.
3. Remove the engine oil filler cap, and then
wipe the engine oil dipstick off with a clean
rag.4. Insert the dipstick into the filler hole (without
screwing it in), and then remove it again to
check the oil level.TIP

The engine oil should be between the minimum
and maximum level marks.
5. 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
1. Engine oil tank filler cap
2. Dipstick
2
1

1. Maximum level mark
2. Minimum level mark
1
2

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may result.
[ECB00851]

6. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
To change the engine oil
1. Place the ATV on a level surface.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Place an oil pan under the engine to collect
the used oil.
4. Remove the engine oil filler cap, and then re-
move the engine oil drain bolt to drain the oil
from the crankcase.
NOTICE:
When remov-
ing the engine oil drain bolt, the compres-
sion spring, oil strainer and O-ring will fall
out. Take care not to lose these
parts.

[ECB00311]

5. Clean the oil strainer with solvent.
6. Check the O-ring for damage and replace it if
necessary.
7. Install the O-ring, oil strainer, compression
spring and drain bolt. Tighten the engine oil
drain bolt to the specified torque.
NOTICE:
Before installing the engine oil drain bolt,
be sure to install the O-ring, compression
spring and oil strainer.
[ECB00321]

1. Engine oil drain bolt
2. O-ring
3. Spring
4. Oil strainer
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8. Refill with the specified amount of the recom-
mended engine oil, and then install and tight-
en the engine oil filler cap.
TIP

Be sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.
NOTICE

ECB00330

Do not use oils with a diesel specification of
“CD” or oils of a higher quality than speci-
fied. In addition, do not use oils labeled “EN-
ERGY CONSERVING II” or higher.

Make sure that no foreign material enters the
crankcase.
9. 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.
10. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
EBU27025
Transmission oil
The transmission oil level should be checked be-
fore each ride. In addition, the transmission oil
must be changed at the intervals specified in the
periodic maintenance and lubrication chart.
To check the transmission oil level
1. Place the ATV on a level surface.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Wait a few minutes until the oil settles, and
then loosen the transmission oil check screw
located at the right side of the crankcase until
oil flows out. Tightening torque:
Engine oil drain bolt:
32 Nm (3.2 m·kgf, 23.1 ft·lbf)
Recommended oil:
See page 10-1.
Oil quantity:
1.25 L (1.32 US qt, 1.10 Imp.qt)

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To change the transmission oil
1. Place the ATV on a level surface.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Place an oil pan under the transmission to col-
lect the used oil.
4. Remove the transmission oil filler bolt and the
transmission oil drain bolt to drain the oil from
the transmission case.
5. Install the drain bolt, and then tighten it to the
specified torque.6. Refill with the specified amount of the recom-
mended transmission oil, and then install and
tighten the oil filler bolt.
NOTICE:
Make sure
that no foreign material enters the trans-
mission case.

[ECB00791]
NOTICE

ECB01061
Make sure that no oil gets on the tires or
wheels.
7. Start the engine, and then let it idle for several
minutes while checking the transmission for
1. Transmission oil drain bolt
1

Tightening torque:
Transmission oil drain bolt:
23 Nm (2.3 m·kgf, 16.6 ft·lbf)
Recommended transmission oil:
See page 10-1.
Oil quantity:
0.6 L (0.63 US qt, 0.53 Imp.qt)
Tightening torque:
Transmission oil filler bolt:
23 Nm (2.3 m·kgf, 16.6 ft·lbf)

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oil leakage. If oil is leaking, immediately turn
off the engine and check for the cause.
8. Turn the engine off, and then check the oil lev-
el and correct it if necessary.
EBU23843
Cleaning the engine and V-belt case air
filter elements
Both air filter elements should be cleaned at the
specified intervals in the periodic maintenance
chart.
Engine air filter element
TIP

There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case.1. Place the ATV on a level surface.
2. Remove the seat. (See page 4-10.)
3. Remove the breather hose, and then loosen
the clamp screw.
1. Check hose
1

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7. Wash the sponge material gently but thor-
oughly in solvent.
WARNING! Always use
parts cleaning solvent to clean the sponge
material. Never use low-flash-point sol-
vents or gasoline to clean the sponge ma-
terial because the engine could catch fire
or explode.
[EWB01941]

8. Squeeze the excess solvent out of the sponge
material and let it dry.
NOTICE:
Do not twist
the sponge material when squeezingit.
[ECB00441]

9. Check the sponge material and replace it if
damaged.
10. Apply Yamaha foam air filter oil or other qual-
ity foam air filter oil to the sponge material.
TIP

The sponge material should be wet but not drip-
ping.
11. Pull the sponge material over the air filter ele-
ment frame.
12. Install the washer and bolt.
NOTICE:
Be sure
to install the washer with the bent edge
facing outward as shown.
[ECB00452]

1. Bolt
2. Washer
3. Sponge material
4. Air filter element frame
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13. Install the air filter element into the air filter
case.
NOTICE:
Make sure that the air filter
element is properly seated in the air filter
case. Never operate the engine with the air
filter element removed. This will allow un-
filtered air to enter the engine, causing rap-
id engine wear and possible engine
damage. Additionally, operation without
the air filter element will affect carburetor
jetting with subsequent poor performance
and possible engine overheating.
[ECB00461]

14. Install the air filter case cover by installing the
screws.15. Install the breather hose and then tighten the
clamp screw.
16. Install the seat.TIP

The 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 ar-
eas. Each time the air filter element maintenance
is performed, check the air inlet of the air filter case
for obstructions. Check the air filter case rubber
joint to the carburetor fittings and the rubber joint
manifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of unfiltered
air entering the engine.
V-belt case air filter element
1. Place the ATV on a level surface.
2. Remove the front carrier by removing the
bolts.
1. Washer
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fore cleaning the spark arrester.
1. Remove the screws.
2. Remove the tailpipe by pulling it out of the
muffler.
3. Tap the tailpipe lightly, and then use a wire
brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing.4. Insert the tailpipe into the muffler and align the
screw holes.
5. Install the screws and tighten them.
WARNING

EWB02340
Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
1. Screw
1

1. Screw
2. Gasket
3. Tailpipe
4. Spark arrester
3
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touching exhaust components.
EBU23930
V-belt case drain plug
After riding in water deep enough to allow it to en-
ter the V-belt case, remove this plug to drain the
water from the case.
TIP

If water drains from the V-belt case after removing
the plug, have a Yamaha dealer check the ATV as
the water may affect other engine parts.
EBU23940
Adjusting the carburetor
The carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the peri-
odic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. Therefore,
most carburetor adjustments should be left to a
Yamaha dealer, who has the necessary profes-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
tenance.
NOTICE

ECB00480
The carburetor has been set and extensively
tested at the Yamaha factory. Changing these
settings without sufficient technical knowl-
edge may result in poor performance of or
damage to the engine.
EBU24000
Adjusting the engine idling speed
The engine idling speed must be checked and, if
necessary, adjusted as follows at the intervals
specified in the periodic maintenance and lubrica-
1. V-belt case drain plug
1