2010 YAMAHA GRIZZLY 125 engine

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EBU18281
Throttle lever
Once the engine is running, movement of the throt-
tle lever will increase the engine speed.
Regulate the speed of the ATV by varying the
throttle position. Because the throttle is spring-
loaded, the ATV will decelerate, and the engine will
return to an idle any time the hand is removed from
the throttle lever.
Before starting the engine, check the throttle to be
sure it is operating smoothly. Make sure it returns
to the idle position as soon as the lever is released.
EBU18322
Speed limiter
Your ATV was delivered with an adjustable speed
limiter. The speed limiter keeps the throttle from
fully opening, even when the throttle lever is
pushed to the maximum.
1. Loosen the locknut.
2. To increase the maximum engine power avail-
able and the maximum speed of the ATV, turn
the adjusting screw in direction (a). To de-
crease the maximum engine power available
and the maximum speed of the ATV, turn the
adjusting screw in direction (b). Do not turn
the adjusting screw out more than 12 mm
(0.47 in) or the throttle cable could be dam-
aged. Always make sure the throttle lever free
play is adjusted to 1.0–3.0 mm (0.04–0.12 in).
(See page 8-24.)
WARNING! Improper ad-
justment of the speed limiter and throttle
could cause throttle cable damage or im-
proper throttle operation. You could lose
control, resulting in an accident.
[EWB00241]

1. Throttle lever
1

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EBU18460
Parking brake
Use the parking brake before starting the engine or
parking the ATV, especially on a slope. Apply the
rear brake lever and push down the lock plate to
apply the parking brake. Squeeze the rear brake
lever to release the parking brake.
WARNING

EWB00220

Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.

Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose
braking performance which could cause an
1. Rear brake lever
1

1. Parking brake lock plate
2. Parking brake lever (locked position)
2
1

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1. Before refueling, turn off the engine and be
sure that no one is sitting on the vehicle. Nev-
er refuel while smoking, or while in the vicinity
of sparks, open flames, or other sources of ig-
nition such as the pilot lights of water heaters
and clothes dryers.
2. Do not overfill the fuel tank. When refueling,
be sure to insert the pump nozzle into the fuel
tank filler hole. Stop filling when the fuel reach-
es the bottom of the filler tube. Because fuel
expands when it heats up, heat from the en-
gine or the sun can cause fuel to spill out of
the fuel tank.3. Wipe up any spilled fuel immediately.
NOTICE:
Immediately wipe off spilled
fuel with a clean, dry, soft cloth, since
fuel may deteriorate painted surfaces
or plastic parts.
[ECB00981]

4. Turn the fuel tank cap fully clockwise to make
sure it is securely closed.
WARNING

EWB02531
Gasoline is poisonous and can cause injury or
death. Handle gasoline with care. Never siphon
gasoline by mouth. If you should swallow
some gasoline or inhale a lot of gasoline vapor,
or get some gasoline in your eyes, see your
doctor immediately. If gasoline spills on your
skin, wash with soap and water. If gasoline
spills on your clothing, change your clothes.
1. Fuel level
2. Fuel tank filler tube
Recommended fuel:
Regular unleaded gasoline only with a re-
search octane number of 91 or higher
Fuel tank capacity:
7.0 L (1.85 US gal, 1.54 Imp.gal)
Fuel reserve amount:
1.3 L (0.34 US gal, 0.29 Imp.gal)

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NOTICE

ECB00070
Use only unleaded gasoline. The use of leaded
gasoline will cause severe damage to internal
engine parts, such as the valves and piston
rings, as well as to the exhaust system.
If knocking (or pinging) occurs, use a gasoline of a
different brand. Use of unleaded fuel will extend
spark plug life and reduce maintenance costs.
EBU18820
Fuel cock
The fuel cock supplies fuel from the tank to the car-
buretor while also filtering it.
The fuel cock lever positions are explained as fol-
lows and shown in the illustrations.
OFF
With the fuel cock lever in this position, fuel will not
flow. Always turn the fuel cock lever to this position
when the engine is not running.
1. Arrow mark positioned over “OFF”
RES
ONFUEL
OFF
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ON
With the fuel cock lever in this position, fuel flows
to the carburetor. Turn the fuel cock lever to this
position when starting the engine and riding.
RES
This indicates reserve. With the fuel cock lever in
this position, the fuel reserve is made available.
Turn the fuel cock lever to this position if you run
out of fuel while riding. When this occurs, refuel as
soon as possible and be sure to turn the fuel cock
lever back to “ON”!

EBU18840
Starter (choke)
Starting a cold engine requires a richer air-fuel mix-
ture, which is supplied by the starter (choke).
Move the starter (choke) in direction (a) to turn on
1. Arrow mark positioned over “ON”
ON
FUEL
RES
OFF
ON
1

1. Arrow mark positioned over “RES”
OFF
ONFUEL RES
RES
1

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the starter (choke).
Move the starter (choke) in direction (b) to turn off
the starter (choke).
See the “Starting a cold engine” section on page
6-1 for proper operation.
EBU18881
Seat
To remove the seat
Pull the seat lock lever upward and pull up the seatat the rear.
To install the seat
Insert the projections on the front of the seat into
the seat holders and push down on the seat at the
rear. Make sure that the seat is securely fitted.

1. Fully open
2. Half open
3. Closed
4. Starter (choke)
(b)
(a)4
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1. Seat lock lever
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EBU19201
PRE-OPERATION CHECKS
EBU19224
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always
follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.
WARNING

EWB00481
Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equip-
ment damage. Do not operate the vehicle if you find any problem. If a problem cannot be corrected
by the procedures provided in this manual, have the vehicle inspected by a Yamaha dealer.
Before using this vehicle, check the following points:
ITEM ROUTINE PAGE
Fuel


Check fuel level in fuel tank, and add recommended fuel if neces-
sary.

Check fuel line for leakage. Correct if necessary.4-6, 5-3
Engine oil

Check oil level in engine, and add recommended oil to specified
level if necessary.

Check ATV for oil leakage. Correct if necessary.5-3, 8-9
Transmission oil

Check oil level in transmission case, and add recommended oil to
specified level if necessary.

Check ATV for oil leakage. Correct if necessary.5-3, 8-12
Front brake

Check operation, and correct if necessary.

Lubricate cable if necessary.

Check lever free play, and adjust if necessary.5-3, 8-26, 8-27
Rear brake

Check operation, and correct if necessary.

Lubricate cable if necessary.

Check lever free play, and adjust if necessary.5-3, 8-26, 8-31

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EBU19541
Fuel
Make sure that there is sufficient fuel in the tank.
(See page 4-6.)
EBU19560
Engine oil
Make sure that the engine oil is at the specified lev-
el. Add oil as necessary. (See page 8-9.)
EBU19580
Transmission oil
Make sure that the transmission oil is at the speci-
fied level. Add oil as necessary. (See page 8-12.)
EBU19651
Front and rear brakes
Brake levers

Check for correct free play in the brake levers. If
the free play is incorrect, adjust it. (See pages
8-27 and 8-31.)

Check operation of the levers. They should
move smoothly and there should be a firm feel-
ing when the brake is applied. If not, have the
ATV checked by a Yamaha dealer.
Brake operation
Test the brakes at slow speed after starting out to
make sure they are working properly. If the brakes
do not provide proper braking performance, check
the brakes for wear. (See page 8-26.)
EBU19761
Throttle lever
Check the operation of the throttle lever. It must
open smoothly and spring back to the idle position
when released. Have a Yamaha dealer correct if
necessary.
EBU19770
Drive chain
Check the condition of the drive chain and check
the drive chain slack. Lubricate and adjust the
drive chain as necessary. (See page 8-32.)
EBU19794
Tires
Check tire pressure regularly to make sure it is at
the recommended specifications. Also check for
wear and damage.
Tire pressure
Use the low-pressure tire gauge to check and ad-
just tire pressures when the tires are cold. Tire