YAMAHA YFM50R 2007 Owners Manual

8-30
1
2
3
4
5
6
78
9
10
11

wheel.
FrontRear
2. Lower the ATV to the ground.
3. Tighten the wheel nuts to the specified
torques.
1. Arrow mark
1

1. Arrow mark
Tightening torques:
Front wheel nut:
28 Nm (2.8 m·kgf, 20 ft·lbf)
Rear wheel nut:
28 Nm (2.8 m·kgf, 20 ft·lbf)
1

8-31
1
2
3
4
5
6
78
9
10
11

EBU25720
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 chart represents a
quick and easy procedure 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.

8-32
1
2
3
4
5
6
78
9
10
11

EBU25791
Troubleshooting chart
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Have a Yamaha dealer
check the ATV.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the electrolyte level, recharge the
battery and check the lead connections.
DryWet
Open the throttle halfway and operate
the electric starter.

9-1
1
2
3
4
5
6
7
89
10
11

EBU25860
CLEANING AND STORAGE
EBU25880
Cleaning
Frequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.
1. Before cleaning the ATV:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, apply
degreaser with a paint brush. Do not apply de-
greaser to the wheel axles.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the job.
CAUTION:

ECB00710
Excessive water pressure may cause water
seepage and deterioration of wheel bearings,
brakes, transmission seals and electrical de-
vices. Many expensive repair bills have result-
ed from improper high-pressure detergentapplications such as those available in coin-
operated car washers.
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or bot-
tle brush is handy for hard-to-reach places.
5. Rinse the ATV off immediately with clean wa-
ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Clean the seat with a vinyl upholstery cleaner
to keep the cover pliable and glossy.
7. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.WARNING

EWB02310
Wet brakes may have reduced stopping ability,
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

9-2
1
2
3
4
5
6
7
89
10
11

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)

9-3
1
2
3
4
5
6
7
89
10
11

the spark plug cap.
6. Lubricate all control cables and the pivoting
points of all levers and pedals.
7. Check and, if necessary, correct the tire air
pressure, and then block up the ATV so that
all of its wheels are off the ground. Alternative-
ly, turn the wheels a little every month in order
to prevent the tires from becoming degraded
in one spot.
8. Cover the muffler outlet with a plastic bag to
prevent moisture from entering it.
9. Remove the battery and fully charge it. Store
it in a cool, dry place and charge it once a
month. Do not store the battery in an exces-
sively cold or warm place [less than 0 °C (30
°F) or more than 30 °C (90 °F)]. For more in-
formation on storing the battery, see page
8-25.
NOTE:

Make any necessary repairs before storing the
ATV.

10-1
1
2
3
4
5
6
7
8
910
11

EBU25960
SPECIFICATIONS
EBU25975
Dimensions:
Overall length:
1537 mm (60.5 in)
Overall width:
825 mm (32.5 in)
Overall height:
915 mm (36.0 in)
Seat height:
618 mm (24.3 in)
Wheelbase:
1030 mm (40.6 in)
Ground clearance:
75 mm (3.0 in)
Minimum turning radius:
2300 mm (91 in)
Weight:
With oil and fuel:
115.0 kg (254 lb)
Engine:
Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
49.0 cm
3

Bore
×
stroke:
39.0
×
41.4 mm (1.54
×
1.63 in)Compression ratio:
10.30 :1
Starting system:
Electric starter
Lubrication system:
Wet sump

Engine oil:
Type:
SAE5W30 or SAE10W30 or SAE10W40 or SAE15W40
or SAE20W40 or SAE20W50
Recommended engine oil grade:
API service SE, SF, SG type or higher
-20˚-10˚0˚
10˚20˚30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30

10-2
1
2
3
4
5
6
7
8
910
11

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

10-3
1
2
3
4
5
6
7
8
910
11

Manufacturer/model:
DUNLOP/KT145
Rear tire:
Type:
Tubeless
Size:
AT16 x 8-7
Manufacturer/model:
DUNLOP/KT145
Loading:
Maximum loading limit:
40.0 kg (88 lb)
(Total weight of rider, cargo, accessories, and tongue)
Tire air pressure (measured on cold tires):
Recommended:
Front:
20.0 kPa (2.9 psi) (0.200 kgf/cm
2

)
Rear:
20.0 kPa (2.9 psi) (0.200 kgf/cm
2

)
Minimum:
Front:
17.0 kPa (2.5 psi) (0.170 kgf/cm
2

)
Rear:
17.0 kPa (2.5 psi) (0.170 kgf/cm
2

)
Maximum:
Front:
23.0 kPa (3.3 psi) (0.230 kgf/cm
2

)
Rear:
23.0 kPa (3.3 psi) (0.230 kgf/cm
2

)
Front wheel:
Wheel type:
Panel wheel
Rim size:
7x5.5AT
Rear wheel:
Wheel type:
Panel wheel
Rim size:
7x6.5AT
Front brake:
Type:
Drum brake
Operation:
Right hand operation
Rear brake:
Type:
Drum brake
Operation:
Left hand operation
Front suspension:
Type:
Leading arm
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
57 mm (2.3 in)
Rear suspension:
Type:
Swingarm

10-4
1
2
3
4
5
6
7
8
910
11

Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
56 mm (2.2 in)
Electrical system:
Ignition system:
CDI
Charging system:
AC magneto
Battery:
Model:
12N7D-3B
Voltage, capacity:
12 V, 7.0 Ah
Bulb voltage, wattage x quantity:
Neutral indicator light:
12 V, 1.7 W
×
1
Fuses:
Main fuse:
5.0 A