engine YAMAHA GRIZZLY 125 2012 Service Manual

8-17
8
EBU2384BCleaning 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 elementTIPThere 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 by pulling it out,
and then loosen the air filter joint screw.
4. Remove the air filter case cover by removing
its screws, then disconnecting the air filter
case cover from the air filter joint.
1. Air filter case check hose
1
1. Breather hose
2. Air filter joint
3. Air filter joint screw
1
3
2
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8 5. Remove the screw and washer shown, and
then pull the sponge material off from the air
filter element frame.
6. 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]
1. Air filter case cover
2. Screw
1 22
2
2
1. Screw
2. Washer
3. Sponge material
4. Air filter element frame
5. Air filter case cover
3 4
21
5
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87. Squeeze the excess solvent out of the sponge
material and let it dry. NOTICE: Do not twist
the sponge material when squeezing it.
[ECB00441]
8. Check the sponge material and replace it if
damaged.
9. Apply Yamaha foam air filter oil or other qual-
ity foam air filter oil to the sponge material.TIPThe sponge material should be wet but not drip-
ping.10. Pull the sponge material over the air filter ele-
ment frame.11. Install the washer and screw. NOTICE: Be
sure to install the washer with its curved
side facing outward as shown.
[ECB00453]
12. 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]
1. Washer
1
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8 13. Connect the air filter case cover to the air filter
joint.
14. Install the air filter case cover by installing the
screws, and then tighten the air filter joint
screw.
15. Install the breather hose.
16. Install the seat.
TIPThe 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.3. Remove the panel by removing the quick fas-
teners, and then pulling it upward as shown.
1. Front carrier bolt
2. Front carrier
2
11
1
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8
WARNING
EWB02340Do 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.EBU30061V-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.TIPIf 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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8
EBU23940Adjusting 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.NOTICEECB00480The 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.
EBU24000Adjusting 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.TIPA diagnostic tachometer is needed to make this
adjustment.1. Start the engine and warm it up.TIPThe 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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8
TIPIf the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.EBU24047Adjusting the throttle lever free play The throttle lever free play should be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.The throttle lever free play should measure 1.0–
3.0 mm (0.04–0.12 in) as shown. Periodically
check the throttle lever free play and, if necessary,
adjust it as follows.
TIPThe engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle le-
ver free play.1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle lever free play, turn
the throttle lever free play adjusting bolt in di-
rection (a). To decrease the throttle lever free
play, turn the adjusting bolt in direction (b).
1. Throttle stop screwEngine idling speed:
1650–1750 r/min
(a)(b) 1
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8
4. Tighten the locknut.
5. Slide the rubber cover to its original position.
EBU24060Valve 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.
EBU29601Brakes Replacement of brake components requires pro-
fessional knowledge. Brake service should be per-
formed by a Yamaha dealer.
WARNING
EWB02571Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident.EBU24090Checking 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 lever free play adjusting bolt
3. Locknut
4. Throttle lever free play
4 3
2
1
(a) (b)
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8To adjust the drive chain slack
1. Place the ATV on a level surface.
2. Loosen the hub stopper bolt locknut and then
the hub stopper bolt.
3. Loosen the axle holding bolts.
4. Loosen the drive chain slack adjusting bolt
locknut. To tighten the drive chain, turn the ad-
justing 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 overloadthe engine as well as other vital parts of
the ATV and can lead to drive chain slip-
page or breakage. To prevent this from oc-
curring, keep the drive chain slack within
the specified limits.
[ECB00542]
5. Tighten the drive chain slack adjusting bolt
locknut and the axle holding bolts to the spec-
ified torques.
1. Hub stopper bolt
2. Hub stopper bolt locknut
3. Axle holding bolt (lower)
4. Axle holding bolt (upper)1
2
34
1. Locknut
2. Drive chain slack adjusting bolt
1
2
(a)
(b)
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82. 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.
1. O-ring
1 1
Recommended lubricant:
Engine oil
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