engine YAMAHA GRIZZLY 125 2011 Service Manual

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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
touching exhaust components.
EBU30060
V-belt case drain screw
After riding in water deep enough to allow it to en-
ter the V-belt case, remove this screw to drain the
water from the case.
TIP

If water drains from the V-belt case after removing
the screw, have a Yamaha dealer check the ATV
as the water may affect other engine parts.
To drain the water from the V-belt case
1. Place the ATV on a level surface.
2. Place a container under the V-belt case, and
then remove the V-belt case drain screw and
its gasket to drain the water from the V-belt
case.
3. Install the V-belt case drain screw and its new
gasket, and then tighten the screw to the
specified torque.
1. V-belt case drain screw
2. Gasket
1
12

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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-
tion chart.
TIP

A diagnostic tachometer is needed to make this
adjustment.
1. Start the engine and warm it up.
TIP

The engine is warm when it quickly responds to the
throttle.
2. Attach the tachometer to the spark plug lead.
3. Check the engine idling speed and, if neces-
sary, adjust it to specification by turning the
throttle stop screw at the carburetor. To in-
crease the engine idling speed, turn the throt-
tle stop screw in direction (a), and to decrease
it, turn the screw in direction (b). Tightening torque:
V-belt case drain screw:
7 Nm (0.7 m·kgf, 5.1 ft·lbf)

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TIP

If the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.
EBU24045
Adjusting the throttle cable free play
The throttle cable free play should be checked
and, if necessary, adjusted at the intervals speci-fied in the periodic maintenance and lubrication
chart.
The throttle cable free play should measure 1.0–
3.0 mm (0.04–0.12 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, adjust it as follows.TIP

The engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle ca-
ble free play.
1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle cable free play, turn
the throttle cable free play adjusting bolt in di-
rection (a). To decrease the throttle cable free
play, turn the adjusting bolt in direction (b).
1. Throttle stop screw
Engine idling speed:
1650–1750 r/min
(a)(b) 1

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4. Tighten the locknut.
5. Slide the rubber cover to its original position.
EBU24060
Valve clearance
The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU29601
Brakes
Replacement of brake components requires pro-
fessional knowledge. Brake service should be per-
formed by a Yamaha dealer.
WARNING

EWB02571
Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident.
EBU24090
Checking the front and rear brake
shoes
The front and rear brake shoes must be checked
for wear at the intervals specified in the periodic
maintenance and lubrication chart. Each brake is
provided with a wear indicator, which allows you to
check the brake shoe wear without having to dis-
assemble the brake. To check the brake shoe
wear, check the position of the wear indicator while
applying the brake. If a brake shoe has worn to the
point that the wear indicator reaches the wear limit
line or mark, have a Yamaha dealer replace the
brake shoes as a set.
1. Rubber cover
2. Throttle cable free play adjusting bolt
3. Locknut
4. Throttle cable free play
4 3
2
1
(a) (b)

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the hub stopper bolt.
3. Loosen the axle holding bolts.
4. Loosen the chain adjusting bolt locknut. To
tighten the drive chain, turn the adjusting bolt
in direction (a). To loosen the drive chain, turn
the adjusting bolt in direction (b), and then
push the wheels forward.
NOTICE:
Improper
drive chain slack will overload the engine
as well as other vital parts of the ATV and
can lead to drive chain slippage or break-age. To prevent this from occurring, keep
the drive chain slack within the specified
limits.
[ECB00542]

5. Tighten the locknut and the axle holding bolts
to the specified torques.
1. Hub stopper bolt
2. Locknut
3. Axle holding bolt (lower)
4. Axle holding bolt (upper)
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1. Locknut
2. Drive chain slack adjusting bolt
1
2
(a)
(b)

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2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a
special O-ring chain lubricant.
NOTICE:
Do
not use engine oil or any other lubricants
for the drive chain, as they may contain
substances that could damage the O-
rings.
[ECB00581]

EBU24901
Checking and lubricating the cables
The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
WARNING

EWB02581

Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could
restrict the operation of controls and lead to
an accident or injury.

Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.
EBU28702
Checking and lubricating the front and
rear brake levers
The operation of the front and rear brake levers
1. O-ring
1

Recommended lubricant:
Engine oil

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EBU25791
Troubleshooting chart
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Have a Yamaha dealer
check the ATV.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the electrolyte level, recharge the
battery and check the lead connections.
DryWet
Open the throttle halfway and operate
the electric starter.

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EBU25860
CLEANING AND STORAGE
EBU25902
Cleaning
Frequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.
1. Before cleaning the ATV:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, apply
degreaser with a paint brush. Do not apply de-
greaser to the chain, sprockets or wheel ax-
les.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the job.
WARNING! Wet brakes may have reduced
stopping ability, increasing the chance of
an accident. Test the brakes after washing.
Apply the brakes several times at slow
speeds to let friction dry out the lin-
ings.
[EWB02311]

NOTICE:
Excessive water pres-sure may cause water seepage and
deterioration of wheel bearings, brakes,
transmission seals and electrical devices.
Many expensive repair bills have resulted
from improper high-pressure detergent
applications such as those available in
coin-operated car washers.
[ECB00711]

4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or bot-
tle brush is handy for hard-to-reach places.
5. Rinse the ATV off immediately with clean wa-
ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Dry the chain and lubricate it to prevent it from
rusting.
7. Clean the seat with a vinyl upholstery cleaner
to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.

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EBU25933
Storage
Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.
NOTICE:
Storing the ATV in a poorly ven-
tilated room or covering it with a tarp while it is
still wet, will allow water and humidity to seep
in and cause rust. To prevent corrosion, avoid
damp cellars, stables (because of the presence
of ammonia) and areas where strong chemi-
cals are stored.

[ECB00721]

Long-term
Before storing your ATV for several months:
1. Follow all the instructions in the “Cleaning”
section of this chapter.
2. Turn the fuel cock lever to “OFF”.
3. Drain the carburetor float chamber by loosen-
ing the drain bolt; this will prevent fuel deposits
from building up. Pour the drained fuel into the
fuel tank.
4. Fill up the fuel tank and add fuel stabilizer (if
available) to prevent the fuel from deteriorat-
ing.5. Perform the following steps to protect the cyl-
inder, piston rings, etc. from corrosion.
a. Remove the spark plug cap and spark
plug.
b. Pour a teaspoonful of engine oil into the
spark plug bore.
c. Install the spark plug cap onto the spark
plug, and then place the spark plug on the
cylinder head so that the electrodes are
grounded. (This will limit sparking during
the next step.)
d. Turn the engine over several times with
the starter. (This will coat the cylinder wall
with oil.)
e. Remove the spark plug cap from the spark
plug, and then install the spark plug and
the spark plug cap.
6. Lubricate all control cables and the pivoting
points of all levers and pedals.
7. Check and, if necessary, correct the tire air
pressure, and then block up the ATV so that
all of its wheels are off the ground. Alternative- Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1 oz
of stabilizer to each gallon of fuel)

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EBU25960
SPECIFICATIONS
EBU2597F
Dimensions:
Overall length:
1700 mm (66.9 in)
Overall width:
990 mm (39.0 in)
Overall height:
980 mm (38.6 in)
Seat height:
685 mm (27.0 in)
Wheelbase:
1080 mm (42.5 in)
Ground clearance:
145 mm (5.7 in)
Minimum turning radius:
2900 mm (114 in)
Weight:
With oil and fuel:
152.0 kg (335 lb)
Noise and vibration level:
Noise level (77/311/EEC):
75.1 dB(A)@3040 r/min
Noise level 40 CFR Part 205 Subpart D (Acceleration):
73.9 dB(A)
Vibration on seat (EN1032, ISO5008):
Will not exceed 0.5 m/s
2

Vibration on handlebar (EN1032, ISO5008):
Will not exceed 2.5 m/s
2

Engine:
Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
124 cm
3

Bore
×
stroke:
49.0
×
66.0 mm (1.93
×
2.60 in)
Compression ratio:
9.00 :1
Starting system:
Electric starter
Lubrication system:
Wet sump

Engine oil:
Recommended brand:
YAMALUBE
Type:
SAE 5W-30, 10W-30, 10W-40, 15W-40, 20W-40 or 20W-
50