2012 YAMAHA GRIZZLY 125 engine

7-6
7 opening, even when the throttle lever is pushed to
the maximum. Turning in the adjusting screw limits
the maximum engine power available and de-
creases the maximum speed of the ATV. Turning
in the adjusting screw decreases top speed, and
turning it out increases top speed. (See page 4-4.)
Loading and accessories
Take extra precautions when driving with a load or
trailer. Follow these instructions and always use
common sense and good judgment when carrying
cargo or towing a trailer.
WARNING
EWB01462Improper loading or towing can increase the
risk of loss of control, an overturn, or other ac-
cident. To reduce the risk of an accident:
Do not exceed the maximum loading limits
for the vehicle (see “MAXIMUM LOADING
LIMIT” in this section or vehicle labeling).
Keep weight on racks centered side to side,
and as low as possible. Be sure cargo is se-
cured – a loose load could change handling
unexpectedly.
Make sure the load does not interfere with
your control or ability to see where you are
going.
Tie down cargo in the trailer securely. Make
sure cargo in the trailer cannot move around.
A shifting load can cause an accident.
Reduce speed and allow more room to stop.
A heavier vehicle takes longer to stop.
Avoid hills and rough terrain. Choose terrain
carefully. Use extreme caution when towing
or carrying a load on inclines.
Turn gradually and go slowly.
1. Adjusting screw
2. Locknut
2
1
U1PY60E0.book Page 6 Friday, March 11, 2011 9:30 AM

7-8
7 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.
U1PY60E0.book Page 8 Friday, March 11, 2011 9:30 AM

7-12
7 Select a large, flat, unpaved area to become famil-
iar with your ATV. Make sure that this area is free
of obstacles and other riders. You should practice
control of the throttle, brakes, shifting procedures,
and turning techniques in this area before trying
more difficult terrain.
Set the parking brake and follow the instruction on
page 6-1 to start the engine. Once it has warmed
up you are ready to begin riding your ATV. With the
engine idling, return the starter knob to the closed
position and shift the drive select lever into the for-
ward position, then release the parking brake. Ap-
ply the throttle slowly and smoothly.
The centrifugal clutch will engage and you will start
to accelerate. If the throttle is applied too abruptly,
the front wheels may lift off the ground, resulting ina loss of directional control. Avoid higher speeds
until you are thoroughly familiar with the operation
of your ATV.
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. Im-
proper use of the brakes can cause the tires to lose
traction, reducing control and increasing the possi-
bility of an accident.
TURNING YOUR ATV
WARNING
EWB01771Always follow proper procedures for turning
as described in this Owner’s Manual. Practice
turning at low speeds before attempting to turn
at faster speeds. Do not turn at speeds too fast
for your skills or the conditions. ATV could go
out of control, causing a collision or overturn.To achieve maximum traction on unpaved surfac-
es, the two rear wheels turn together at the same
speed. Therefore, unless the wheel on the inside
of the turn is allowed to slip or lose some traction,
the ATV will resist turning. A special turning tech-
nique must be used to allow the ATV to make turns
quickly and easily. It is essential that this skill be
learned first at low speed.
U1PY60E0.book Page 12 Friday, March 11, 2011 9:30 AM

7-17
7When 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.
Use caution while descending a hill with loose or
slippery surfaces. Braking ability and traction may
be adversely affected by these surfaces. Improper
braking may also cause a loss of traction. Gradual-
ly apply only the rear brake.
Whenever possible, ride your ATV straight down-
hill. Avoid sharp angles which could allow the ATV
to tip or roll over. Carefully choose your path and
ride no faster than you will be able to react to ob-
stacles which may appear.
CROSSING A SLOPE
WARNING
EWB01632Improperly crossing hills or turning on hills
could cause loss of control or cause the ATV to
overturn.
Always follow proper procedures as de-
scribed in the Owner’s Manual.
Avoid hills with excessively slippery or loose
surfaces.
Avoid crossing the side of a steep hill.
U1PY60E0.book Page 17 Friday, March 11, 2011 9:30 AM

8-1
8
EBU28783
PERIODIC MAINTENANCE AND ADJUSTMENT
EBU21674Periodic 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
EWB02562Turn 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 2-3 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
charts should be considered as a general guide
under normal riding conditions. However, DE-
PENDING ON THE WEATHER, TERRAIN, GEO-
GRAPHICAL LOCATION, AND INDIVIDUAL
USE, THE MAINTENANCE INTERVALS MAY
NEED TO BE SHORTENED.
U1PY60E0.book Page 1 Friday, March 11, 2011 9:30 AM

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.√√√
U1PY60E0.book Page 3 Friday, March 11, 2011 9:30 AM

8-5
8
EBU21865General maintenance and lubrication chart 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
1Engine and V-belt
case air filter ele-
ment Clean and replace if necessary.Every 20–40 hours (more often in wet or
dusty areas)
2*Front brakeCheck operation and correct if necessary.
Check brake lever free play and adjust if neces-
sary.√√√√√
Replace brake shoes. Whenever worn to the limit
3*Rear brakeCheck operation and correct if necessary.
Check brake lever free play and adjust if neces-
sary.√√√√√
Replace brake shoes. Whenever worn to the limit
U1PY60E0.book Page 5 Friday, March 11, 2011 9:30 AM

8-7
8
14*Steering systemCheck operation and repair or replace if damaged.
Check toe-in and adjust if necessary.√√√√√
15 Engine oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√ √√√
16 Engine oil strainerClean.√√√
17 Transmission oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√√
18*Moving parts and
cablesLubricate.√√√√
19*Throttle leverCheck operation.
Check throttle lever free play, and adjust if neces-
sary.
Lubricate cable and lever housing.√√√√√
20*Front and rear brake
switchesCheck operation and correct if necessary.√√√√√
21*Lights and switchesCheck operation and correct if necessary.
Adjust headlight beams.√√√√√
22*BatteryCheck electrolyte level and specific gravity, and
correct if necessary.
Make sure that the breather hose is properly rout-
ed.√√√√√ 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 320U1PY60E0.book Page 7 Friday, March 11, 2011 9:30 AM