Page 22 of 78
INSTRUMENT AND CONTROL FUNCTIONS
3-1
3
EAU40340
Main switch The main switch controls the ignition
system. The main switch positions are
described below.
EAU10630
ON
All electrical systems are supplied with
power, and the engine can be started.
The key cannot be removed.
EAU10660
OFF
All electrical systems are off. The key
can be removed.
EAU12347
Handlebar switches Left
Right
EAU12660
Engine stop switch“/”
Set this switch to“” before starting
the engine. Set this switch to“” to
stop the engine in case of an emergen-
cy, such as when the vehicle overturns
or when the throttle cable is stuck.
EAU12710
Start switch“”
Push this switch to crank the engine
with the starter.CAUTION:
ECA10050
See page 5-1 for starting instruc-tions prior to starting the engine.
1. Engine stop switch“/”
1. Start switch“”
1
U5B680E0.book Page 1 Tuesday, July 17, 2007 9:11 AM
Page 67 of 78
PERIODIC MAINTENANCE AND MINOR REPAIR
6-31
6
NOTE:The drive chain does not need to be
disassembled in order to remove andinstall the wheel.
8. Remove the wheel.
EAU41652
To install the rear wheel
1. Install the drive chain onto the rear
sprocket.
2. Insert the wheel axle from the
right-hand side.
3. Adjust the drive chain slack. (See
page 6-20.)
4. Lower the rear wheel so that it is
on the ground.5. Install the brake rod onto the brake
camshaft lever, and then install the
brake pedal free play adjusting nut
onto the brake rod.
6. Connect the brake torque rod to
the brake shoe plate by installing
the bolt and nut, and then tighten
the nut to the specified torque.
7. Insert a new cotter pin.
8. Tighten the axle nut to the speci-
fied torque.
9. Adjust the brake pedal free play.
(See page 6-18.)
EAU25850
Troubleshooting Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur dur-
ing operation. Any problem in the fuel,
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 your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look like
Yamaha parts, but they are often inferi-
or, have a shorter service life and can
lead to expensive repair bills.
Tightening torques:
Brake torque rod nut:
26 Nm (2.6 m·kgf, 19 ft·lbf)
Axle nut:
60 Nm (6.0 m·kgf, 43 ft·lbf)
U5B680E0.book Page 31 Tuesday, July 17, 2007 9:11 AM
Page 68 of 78
PERIODIC MAINTENANCE AND MINOR REPAIR
6-32
6
EAU25901
Troubleshooting chart
WARNING
EWA10840
Keep away open flames and do not smoke while checking or working on the fuel system.
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 vehicle.
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 vehicle.
The engine does not start.
Have a Yamaha dealer
check the vehicle.
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 battery lead connections,
and charge the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
U5B680E0.book Page 32 Tuesday, July 17, 2007 9:11 AM
Page 74 of 78
SPECIFICATIONS
8-2
8
Transmission:Primary reduction system:
Spur gear
Primary reduction ratio:
67/18 (3.722)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
35/14 (2.500)
Transmission type:
Constant mesh 4-speed
Operation:
Left foot operation
Gear ratio:
1st:
38/12 (3.166)
2nd:
33/17 (1.941)
3rd:
29/21 (1.380)
4th:
23/21 (1.095)Chassis:Frame type:
Steel tube backbone
Caster angle:
26.00 °
Trail:
60.0 mm (2.36 in)Front tire:Type:
With tube
Size:
2.50-14 4PRManufacturer/model:
CHEN SHIN/C-803
Rear tire:Type:
With tube
Size:
3.00-12 4PR
Manufacturer/model:
CHEN SHIN/C-803Loading:Maximum rider weight:
60.0 kg (132 lb)Tire air pressure (measured on cold
tires):
Front:
100 kPa (15 psi) (1.00 kgf/cm²)
Rear:
100 kPa (15 psi) (1.00 kgf/cm²)
Front wheel:Wheel type:
Spoke wheel
Rim size:
14x1.40Rear wheel:Wheel type:
Spoke wheel
Rim size:
12x1.60Front brake:Type:
Drum brake
Operation:
Right hand operation
Rear brake:Type:
Drum brake
Operation:
Right foot operationFront suspension:Type:
Telescopic fork
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
115.0 mm (4.53 in)Rear suspension:Type:
Swingarm (monocross)
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel:
110.0 mm (4.33 in)Electrical system:Ignition system:
DC. CDI
Charging system:
AC magnetoBattery:Model:
GT4B-5
Voltage, capacity:
12 V, 2.5 AhFuse:Fuse:
10.0 A
U5B680E0.book Page 2 Tuesday, July 17, 2007 9:11 AM
