2008 YAMAHA YFM50R fuel cap

EBU17420
TABLE OF CONTENTS
SAFETY INFORMATION .............................. 1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS ............................ 2-1
DESCRIPTION .............................................. 3-1
Left view ..................................................... 3-1
Right view................................................... 3-1
Controls and instruments ........................... 3-2
INSTRUMENT AND CONTROL
FUNCTIONS .................................................. 4-1
Main switch ............................................... 4-1
Indicator light ............................................. 4-1
Handlebar switches ................................... 4-2
Engine stop switch with lanyard ................ 4-2
Throttle lever ............................................. 4-4
Speed limiter ............................................. 4-5
Front brake lever ....................................... 4-6
Rear brake lever ........................................ 4-6
Parking brake ............................................ 4-6
Drive select lever ....................................... 4-7
Fuel tank cap ............................................. 4-7
Fuel ........................................................... 4-8
Fuel cock ................................................... 4-9Choke ...................................................... 4-10
Seat ......................................................... 4-11
PRE-OPERATION CHECKS ..........................5-1
Pre-operation check list ............................. 5-1
Fuel ............................................................ 5-3
Engine oil ................................................... 5-3
Final gear oil .............................................. 5-3
Front and rear brakes ................................ 5-3
Throttle lever .............................................. 5-4
Tires ........................................................... 5-4
Measuring the tire pressure ....................... 5-5
Tire wear limit ............................................ 5-6
Chassis fasteners ...................................... 5-6
Instruments, lights and switches ................ 5-6
Battery ....................................................... 5-6
OPERATION...................................................6-1
Starting a cold engine ................................ 6-1
Starting a warm engine .............................. 6-3
Shifting ....................................................... 6-3
Engine break-in .......................................... 6-5
Parking ....................................................... 6-5
Parking on a slope ..................................... 6-6
Accessories and loading ............................ 6-7

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23
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EBU17712
Controls and instruments
NOTE:

The ATV you have purchased may differ slightly
from the figures shown in this manual.
1. Rear brake lever
2. Parking brake
3. Neutral indicator light
4. Front brake lever
5. Throttle lever
6. Main switch
7. Fuel tank cap
8. Handlebar switches
123
4
8
765

4-7
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34
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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
accident. You could also wear out the brakes
prematurely.
EBU18630
Drive select lever
The drive select lever is located on the left side of
the engine. Use the drive select lever to shift the
transmission into drive or neutral.
EBU18720
Fuel tank cap
Remove the fuel tank cap by turning it counter-
clockwise.
1. Parking brake lock plate
1

1. Drive select lever
2. Drive position
3. Neutral position
1
2
3

4-8
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34
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EBU18752
Fuel
Make sure that there is sufficient fuel in the tank.
Fill the fuel tank to the bottom of the filler tube as
shown.NOTE:
If knocking or pinging occurs, use a different brand
1. Fuel tank cap
1

1. Fuel level
2. Filler tube
Recommended fuel:
UNLEADED GASOLINE ONLY
For Europe: Regular unleaded gasoline only
with a research octane number of 91 or high-
er
Fuel tank capacity:
6.8 L (1.80 US gal) (1.50 Imp.gal)
Fuel reserve amount:
0.9 L (0.24 US gal) (0.20 Imp.gal)

4-9
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34
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of gasoline or higher octane grade.
CAUTION:

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.
WARNING

EWB00310

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is overfilled,
fuel could spill out due to heat from the en-
gine or the sun.

Be careful not to spill fuel, especially on the
engine or exhaust pipe which can cause a
fire and severe injury. Wipe up any spilled
fuel immediately.

Do not refuel right after the engine has been
running and is still very hot.

Be sure the fuel tank cap is closed securely.
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
1

5-3
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3
45
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EBU19540
Fuel
Make sure that there is sufficient fuel in the tank.
(See page 4-8.)
WARNING

EWB00520

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is overfilled,
fuel could spill out due to heat from the en-
gine or the sun.

Be careful not to spill fuel, especially on the
engine or exhaust pipe which can cause a
fire and severe injury. Wipe up any spilled
fuel immediately.

Do not refuel right after the engine has been
running and is still very hot.

Be sure the fuel tank cap is closed securely.
EBU19560
Engine oil
Make sure that the engine oil is at the specified lev-
el. Add oil as necessary. (See page 8-9.)
EBU19590
Final gear oil
Make sure that the final gear oil is at the specified
level. Add oil as necessary. (See page 8-12.)
EBU19650
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
8-21 and 8-23.)

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 8-20.)
WARNING

EWB00570
Always check the brakes at the start of every
ride. Do not ride the ATV if you find any prob-
lem with the brakes or you could lose braking
ability, which could lead to an accident. If a
problem cannot be corrected by the adjust-
ment procedures provided in this manual, have
the ATV checked by a Yamaha dealer.

9-2
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linings.
EBU25932
Storage
Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.
CAUTION:

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-
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 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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910
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Engine oil quantity:
Periodic oil change:
0.80 L (0.85 US qt) (0.70 Imp.qt)
Final gear oil:
Type:
SAE80 API GL-4 Hypoid gear oil
Quantity:
0.12 L (0.13 US qt) (0.11 Imp.qt)
Air filter:
Air filter element:
Wet element
Fuel:
Recommended fuel:
Regular unleaded gasoline only (EUR)
Unleaded gasoline only (AUS)(NZL)
Fuel tank capacity:
6.8 L (1.80 US gal) (1.50 Imp.gal)
Fuel reserve amount:
0.9 L (0.24 US gal) (0.20 Imp.gal)
Carburetor:
Manufacturer:
MIKUNI
Type x quantity:
VM16SH x 1
Spark plug (s):
Manufacturer/model:
NGK/CR7HSA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Clutch:
Clutch type:
Wet, multiple-disc automatic
Transmission:
Primary reduction system:
Spur gear
Primary reduction ratio:
65/20 (3.250)
Secondary reduction system:
Shaft drive
Secondary reduction ratio:
19/18
×
34/10 (3.588)
Transmission type:
Constant mesh 1-speed
Operation:
Left hand operation
1st:
38/14 (2.714)
Chassis:
Frame type:
Steel tube frame
Caster angle:
1.0 °
Trail:
3.4 mm (0.13 in)
Front tire:
Type:
Tubeless
Size:
AT16 x 7-7