
8-30
1
2
3
4
5
6
78
9
10
11
5. Move the throttle lever a few times and re-
check the position.
6. Install the fuel tank, side cover, radiator cover
and air filter case cover.
7. Connect the fuel hoses.
8. Install the seat.
EBU24020
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.
The carburetor synchronization and the throttle
cable free play must be checked, and adjusted if
necessary, before adjusting the engine idling
speed.
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. Turn in both pilot air screws until they lightly
seat.
4. Turn out both pilot air screws to specification.
(See the “Changing the carburetor settings”
section on the page 8-22.)
1. Adjusting nut
2. Locknut
1
2

8-51
1
2
3
4
5
6
78
9
10
11
EBU25740
Troubleshooting
Although Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the fu-
el, compression, or ignition systems, for example,
can cause poor starting and loss of power.
The following troubleshooting charts represent
quick and easy procedures for checking these vital
systems yourself. However, should your ATV re-
quire any repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary tools, expe-
rience, and know-how to service the ATV properly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.WARNING
EWB02280
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-
lot lights from water heaters or furnaces.
Tightening torques:
Front wheel nut:
45 Nm (4.5 m·kgf, 32 ft·lbf)
Rear wheel nut:
45 Nm (4.5 m·kgf, 32 ft·lbf)

8-52
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2
3
4
5
6
78
9
10
11
EBU25841
Troubleshooting charts
Starting problems or poor engine performance
Check the fuel level in
the fuel tank.1. Fuel
There is
enough fuel.
There is
no fuel.
Supply fuel.
Operate the kickstarter.2. Compression
There is compression.
There is
no compression.Check the ignition.
Have a Yamaha dealer
check the ATV.
Remove the spark plugs
and check the electrodes.3. Ignition
Wet
Dry
Wipe off with a dry cloth and correct the
spark plug gaps, or replace the spark plugs.Have a Yamaha dealer check the ATV.The engine does not start.
Have a Yamaha dealer check the ATV.
Open the throttle halfway and operate
the kickstarter.
Check the compression.
The engine does not start.
Check the compression.

9-2
1
2
3
4
5
6
7
89
10
11
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
linings.
EBU25951
Storage
Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.
NOTICE
ECB00720
Storing the ATV in a poorly ventilated 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 ammo-
nia) and areas where strong chemicals are
stored.
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-
inders, piston rings, etc. from corrosion.
a. Remove the spark plug caps and spark
plugs.
b. Pour a teaspoonful of engine oil into each
spark plug bore.
c. Install the spark plug caps onto the spark
plugs, and then place the spark plugs on
the cylinder head so that the electrodes
are grounded. (This will limit sparking dur-
ing the next step.)
d. Turn the engine over several times with
the starter. (This will coat the cylinder walls Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1 oz
of stabilizer to each gallon of fuel)

10-1
1
2
3
4
5
6
7
8
910
11
EBU25960
SPECIFICATIONS
EBU2597B
Dimensions:
Overall length:
1855 mm (73.0 in)
Overall width:
1100 mm (43.3 in)
Overall height:
1080 mm (42.5 in)
Seat height:
800 mm (31.5 in)
Wheelbase:
1280 mm (50.4 in)
Ground clearance:
135 mm (5.3 in)
Minimum turning radius:
3600 mm (142 in)
Weight:
With oil and fuel:
187.0 kg (412 lb)
Noise and vibration level:
Noise level (77/311/EEC):
82.7 dB(A) (EUR)
Vibration on seat (EN1032, ISO5008):
Will not exceed 0.5 m/s
2
(EUR)
Vibration on handlebar (EN1032, ISO5008):
Will not exceed 2.5 m/s
2
(EUR)
Engine:
Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Forward-inclined parallel 2-cylinder
Displacement:
347.0 cm
3
Bore
×
stroke:
64.0
×
54.0 mm (2.52
×
2.13 in)
Compression ratio:
6.50 :1
Starting system:
Kickstarter
Lubrication system:
Premix
Type:
YAMALUBE 2-R, Castrol R30, A545, A747
Engine oil quantity:
Premix ratio (1):
YAMALUBE R 24:1
Transmission oil:
Type:
SAE 10W-30 type SE motor oil (EUR)
YAMALUBE 4 (10W-40) or SAE 10W-40 type SE motor
oil (AUS)(NZL)
Quantity:
1.5 L (1.59 US qt, 1.32 Imp.qt)

10-2
1
2
3
4
5
6
7
8
910
11
Cooling system:
Coolant reservoir capacity (up to the maximum level mark):
0.28 L (0.30 US qt, 0.25 Imp.qt)
Radiator capacity (including all routes):
1.50 L (1.59 US qt, 1.32 Imp.qt)
Air filter:
Air filter element:
Wet element
Fuel:
Recommended fuel:
Premium unleaded gasoline only
Fuel tank capacity:
12.0 L (3.17 US gal, 2.64 Imp.gal)
Fuel reserve amount:
2.5 L (0.66 US gal, 0.55 Imp.gal)
Carburetor:
Manufacturer:
MIKUNI
Type
×
quantity:
VM26SS x 2
Spark plug (s):
Manufacturer/model:
NGK/BR8ES
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Clutch:
Clutch type:
Wet, multiple-disc
Transmission:
Primary reduction system:
Helical gearPrimary reduction ratio:
66/23 (2.869)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
41/14 (2.929)
Transmission type:
Constant mesh 6-speed
Operation:
Left foot operation
1st:
32/13 (2.461)
2nd:
29/16 (1.812)
3rd:
27/18 (1.500)
4th:
25/20 (1.250)
5th:
23/22 (1.045)
6th:
21/24 (0.875)
Chassis:
Frame type:
Steel tube frame
Caster angle:
9.0 °
Trail:
40.0 mm (1.57 in)
Front tire:
Type:
Tubeless

INDEX
A
Accessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-17
B
Brake and clutch levers, checking and lubricating ....... 8-43
Brake fluid, changing.................................................... 8-35
Brake fluid level, checking............................................ 8-33
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ...................... 8-35
Brake light switches ..................................................... 8-38
Brake pads, checking the front and rear ...................... 8-32
Brake pedal .................................................................... 4-5
Brake pedal, checking and lubricating ......................... 8-43
Brake pedal position, checking .................................... 8-36
Brakes, front and rear .................................................... 5-3
C
Cables, checking and lubricating ................................. 8-43
Carburetor settings, changing ...................................... 8-22
Chassis fasteners........................................................... 5-7
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-4
Clutch lever free play, adjusting ................................... 8-39
Coolant ................................................................. 5-3
,
8-12
D
Drive chain ..................................................................... 5-4
Drive chain, lubricating ................................................. 8-42Drive chain slack .......................................................... 8-40
E
Engine break-in .............................................................. 6-4
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-30
Engine, starting a warm ................................................. 6-2
Engine stop switch ......................................................... 4-2
F
Fuel ................................................................................ 4-8
Fuel and 2-stroke engine oil mixing ratio ....................... 5-3
Fuel cock ........................................................................ 4-9
Fuel tank cap.................................................................. 4-7
H
Handlebar switches ........................................................ 4-2
Headlight beam, adjusting............................................ 8-48
Headlight bulb, replacing.............................................. 8-45
I
Identification numbers .................................................. 11-1
Instruments, lights and switches .................................... 5-7
K
Key identification number ............................................. 11-1
Kickstarter ...................................................................... 4-7
L
Label locations ............................................................... 2-1
Light switch .................................................................... 4-2