2007 YAMAHA CYGNUS 125 fuel cap

TABLE OF CONTENTS
SAFETY INFORMATION
...................1-1
Further safe-riding points .................1-4
DESCRIPTION
...................................2-1
Left view ...........................................2-1
Right view .........................................2-2
Controls and instruments..................2-3
INSTRUMENT AND CONTROL
FUNCTIONS
........................................3-1
Main switch ......................................3-1
Keyhole cover ..................................3-2
Indicator and warning lights .............3-2
Speedometer ...................................3-3
Multi-function display .......................3-3
Handlebar switches .........................3-5
Front brake lever .............................3-6
Rear brake lever ..............................3-7
Fuel tank cap ...................................3-7
Fuel ..................................................3-8
Catalytic converter ...........................3-9
Kickstarter ........................................3-9
Seat .................................................3-9
Storage compartments ..................3-10
Sidestand .......................................3-11
Sidestand switch operation check .3-12
PRE-OPERATION CHECKS
...............4-1
Pre-operation check list ...................4-2
OPERATION AND IMPORTANT
RIDING POINTS
.................................. 5-1
Starting the engine .......................... 5-1
Starting off ....................................... 5-2
Acceleration and deceleration ......... 5-2
Braking ............................................ 5-2
Tips for reducing fuel
consumption ................................ 5-3
Engine break-in ............................... 5-3
Parking ............................................ 5-4
PERIODIC MAINTENANCE AND
MINOR REPAIR
.................................. 6-1
Owner’s tool kit ................................ 6-1
Periodic maintenance and lubrication
chart ............................................. 6-3
Removing and installing panels ...... 6-6
Checking the spark plug .................. 6-7
Engine oil and oil strainer ................ 6-9
Final transmission oil ..................... 6-11
Air filter and V-belt case air filter
elements .................................... 6-12
Checking the throttle cable free
play ............................................ 6-14
Valve clearance ............................. 6-14
Tires .............................................. 6-14
Cast wheels ................................... 6-16
Adjusting the rear brake lever free
play ............................................ 6-16
Checking the front brake pads and
rear brake shoes ........................ 6-17Checking the front brake fluid
level ........................................... 6-18
Changing the brake fluid ............... 6-19
Checking and lubricating the
cables ........................................ 6-19
Checking and lubricating the throttle
grip and cable ............................ 6-20
Lubricating the front and rear brake
levers ......................................... 6-20
Checking and lubricating the
centerstand and sidestand ........ 6-20
Checking the front fork .................. 6-21
Checking the steering ................... 6-21
Checking the wheel bearings ........ 6-22
Battery ........................................... 6-22
Replacing the fuses ...................... 6-24
Replacing the headlight bulb ........ 6-25
Replacing a front turn signal light
bulb ............................................ 6-26
Replacing the tail/brake light bulb or
a rear turn signal light bulb ........ 6-27
Replacing an auxiliary light bulb ... 6-27
Troubleshooting ............................ 6-28
Troubleshooting chart ................... 6-29
SCOOTER CARE AND
STORAGE
........................................... 7-1
Matte color caution .......................... 7-1
Care ................................................ 7-1
Storage ........................................... 7-3

SAFETY INFORMATION
1-3
1
When loading within this weight limit,
keep the following in mind:

Cargo and accessory weight
should be kept as low and close to
the scooter as possible. Make sure
to distribute the weight as evenly
as possible on both sides of the
scooter to minimize imbalance or
instability.

Shifting weights can create a sud-
den imbalance. Make sure that ac-
cessories and cargo are securely
attached to the scooter before
riding. Check accessory mounts
and cargo restraints frequently.

Never attach any large or heavy
items to the handlebar, front fork,
or front fender. Such items can
create unstable handling or a slow
steering response.
Accessories
Genuine Yamaha accessories have
been specifically designed for use on
this scooter. Since Yamaha cannot test
all other accessories that may be avail-
able, you must personally be responsi-
ble for the proper selection, installationand use of non-Yamaha accessories.
Use extreme caution when selecting
and installing any accessories.
Keep the following guidelines in mind,
as well as those provided under “Load-
ing” when mounting accessories.


Never install accessories or carry
cargo that would impair the perfor-
mance of your scooter. Carefully
inspect the accessory before using
it to make sure that it does not in
any way reduce ground clearance
or cornering clearance, limit sus-
pension travel, steering travel or
control operation, or obscure lights
or reflectors.

Accessories fitted to the handle-
bar or the front fork area can
create instability due to improper
weight distribution or aerody-
namic changes. If accessories
are added to the handlebar or
front fork area, they must be as
lightweight as possible and
should be kept to a minimum.

Bulky or large accessories may
seriously affect the stability of
the scooter due to aerodynamiceffects. Wind may attempt to lift
the scooter, or the scooter may
become unstable in cross
winds. These accessories may
also cause instability when
passing or being passed by
large vehicles.

Certain accessories can dis-
place the operator from his or
her normal riding position. This
improper position limits the free-
dom of movement of the opera-
tor and may limit control ability,
therefore, such accessories are
not recommended.

Use caution when adding electri-
cal accessories. If electrical acces-
sories exceed the capacity of the
scooter’s electrical system an
electric failure could result, which
could cause a dangerous loss of
lights or engine power.
Gasoline and exhaust gas

GASOLINE IS HIGHLY FLAMMA-
BLE:

Always turn the engine off when
refueling.

2-1
1
2
3
4
5
6
7
8
9

DESCRIPTION
EAU10410
Left view
4
3 2
1
6
5

1. Fuel tank cap (page 3-7)
2. Rear storage compartment (page 3-10)
3. Rear turn signal light (page 6-27)
4. Tail/brake light (page 6-27)
5. Kickstarter (page 3-9)
6. Air filter (page 6-12)

INSTRUMENT AND CONTROL FUNCTIONS
3-7
2
34
5
6
7
8
9

EAU12950
Rear brake lever
The rear brake lever is located on the
left handlebar grip. To apply the rear
brake, pull this lever toward the handle-
bar grip.
EAU13071
Fuel tank cap
To open the fuel tank cap
Open the fuel tank cap lock cover, in-
sert the key into the lock, and then turn
it 1/4 turn clockwise. The lock will be re-
leased and the fuel tank cap can be
opened.
To close the fuel tank cap
1. Push the fuel tank cap into position
with the key inserted in the lock.
2. Turn the key counterclockwise to
the original position, remove it, and
then close the lock cover.
NOTE:

The fuel tank cap cannot be closed un-less the key is in the lock. In addition,
the key cannot be removed if the cap is
not properly closed and locked.
WARNING

EWA11090
Make sure that the fuel tank cap is
properly closed before riding.
1. Rear brake lever
ZAUM00**
1

1. Fuel tank cap lock cover
ZAUM00**
1

INSTRUMENT AND CONTROL FUNCTIONS
3-8
1
2
3
4
5
6
7
8
9

EAU13220
Fuel
Make sure that there is sufficient fuel in
the tank. When refueling, be sure to in-
sert the pump nozzle into the fuel tank
filler hole and to fill the tank to the bot-
tom of the filler tube as shown.
WARNING

EWA10880

Do not overfill the fuel tank, oth-
erwise it may overflow when the
fuel warms up and expands.

Avoid spilling fuel on the hot en-
gine.
CAUTION:

ECA10070
Immediately wipe off spilled fuel
with a clean, dry, soft cloth, since
fuel may deteriorate painted surfac-
es or plastic parts.
EAU33520
CAUTION:

ECA11400
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.
Your Yamaha engine has been de-
signed to use regular unleaded gaso-
line with a research octane number of
91 or higher. If knocking (or pinging) oc-
curs, use a gasoline of a different brand
or premium unleaded fuel. Use of un-leaded fuel will extend spark plug life
and reduce maintenance costs.
1. Fuel tank filler tube
2. Fuel level
ZAUM00**
1
2

Recommended fuel:
REGULAR UNLEADED GASOLINE
ONLY
Fuel tank capacity:
7.4 L (1.96 US gal) (1.63 Imp.gal)

SCOOTER CARE AND STORAGE
7-4
1
2
3
4
5
6
7
8
9
fuel from deteriorating.
3. Perform the following steps to pro-
tect the cylinder, 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 spark-
ing 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 the
spark plug cap.
WARNING

EWA10950
To prevent damage or injury from
sparking, make sure to ground the
spark plug electrodes while turning
the engine over.
4. Lubricate all control cables and thepivoting points of all levers and
pedals as well as of the sidestand/
centerstand.
5. Check and, if necessary, correct
the tire air pressure, and then lift
the scooter so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
6. Cover the muffler outlet with a
plastic bag to prevent moisture
from entering it.
7. 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 ex-
cessively cold or warm place [less
than 0 °C (30 °F) or more than 30
°C (90 °F)]. For more information
on storing the battery, see page
6-22.
NOTE:

Make any necessary repairs before
storing the scooter.

8-1
2
3
4
5
6
7
89

SPECIFICATIONS
EAU2633J
Dimensions:
Overall length:
1855 mm (73.0 in)
Overall width:
685 mm (27.0 in)
Overall height:
1130 mm (44.5 in)
Seat height:
785 mm (30.9 in)
Wheelbase:
1295 mm (51.0 in)
Ground clearance:
115 mm (4.53 in)
Minimum turning radius:
1900 mm (74.8 in)
Weight:
With oil and fuel:
120.0 kg (265 lb)
Engine:
Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
125.0 cm
3

Bore
×
stroke:
52.4
×
57.9 mm (2.06
×
2.28 in)
Compression ratio:
10.00 :1
Starting system:
Electric starter and kickstarterLubrication system:
Wet sump

Engine oil:
Type:
SAE20W40
Recommended engine oil grade:
API service SG type or higher, JASO stan-
dard MA
Engine oil quantity:
Periodic oil change:
0.90 L (0.95 US qt) (0.79 Imp.qt)
Final transmission oil:
Type:
SAE10W30 type SE motor oil
Quantity:
0.11 L (0.12 US qt) (0.10 Imp.qt)
Air filter:
Air filter element:
Oil-coated paper element
Fuel:
Recommended fuel:
Regular unleaded gasoline onlyFuel tank capacity:
7.4 L (1.96 US gal) (1.63 Imp.gal)
Fuel injector:
Manufacturer:
AISAN
Model/quantity:
4P91 01 / 1
Spark plug (s):
Manufacturer/model:
NGK/CR7E
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Clutch:
Clutch type:
Dry, centrifugal automatic
Transmission:
Primary reduction system:
Helical gear
Primary reduction ratio:
38/13 (2.923)
Secondary reduction system:
Helical gear
Secondary reduction ratio:
40/12 (3.333)
Transmission type:
V-belt automatic
Operation:
Centrifugal automatic type
Chassis:
Frame type:
Steel tube backbone
Caster angle:
27.00 °
-20 -10 0
10 20 30
40
50 ˚C
SAE 10W-30
SAE 15W-40SAE 20W-40SAE 20W-50
SAE 10W-40

INDEX
A
Acceleration and deceleration................... 5-2
Air filter and V-belt case air filter
elements ............................................... 6-12
Auxiliary light bulb, replacing .................. 6-27
B
Battery..................................................... 6-22
Brake fluid, changing .............................. 6-19
Brake fluid level, checking ...................... 6-18
Brake lever, front....................................... 3-6
Brake lever, rear ....................................... 3-7
Brake levers, lubricating.......................... 6-20
Brake pads and shoes, checking ............ 6-17
Braking ...................................................... 5-2
C
Cables, checking and lubricating ............ 6-19
Care .......................................................... 7-1
Catalytic converter .................................... 3-9
Centerstand and sidestand, checking and
lubricating ............................................. 6-20
D
Dimmer switch .......................................... 3-6
E
Engine break-in ......................................... 5-3
Engine oil and oil strainer.......................... 6-9
Engine trouble warning light...................... 3-3
F
Final transmission oil .............................. 6-11
Front fork, checking ................................ 6-21
Fuel ........................................................... 3-8
Fuel consumption, tips for reducing .......... 5-3
Fuel tank cap ............................................ 3-7
Fuses, replacing...................................... 6-24
H
Handlebar switches ...................................3-5
Headlight bulb, replacing .........................6-25
High beam indicator light ...........................3-2
Horn switch ................................................3-6
I
Identification numbers................................9-1
Indicator and warning lights .......................3-2
K
Keyhole cover ............................................3-2
Key identification number ..........................9-1
Kickstarter ..................................................3-9
M
Main switch ................................................3-1
Matte color, caution ...................................7-1
Model label ................................................9-2
Multi-function display .................................3-3
P
Panels, removing and installing .................6-6
Parking.......................................................5-4
Part locations .............................................2-1
Periodic maintenance and lubrication
chart ........................................................6-3
Pre-operation check list .............................4-2
R
Rear brake lever free play, adjusting .......6-16
S
Safe-riding points .......................................1-4
Safety information ......................................1-1
Seat ...........................................................3-9
Sidestand .................................................3-11
Sidestand switch operation check ...........3-12
Spark plug, checking .................................6-7
Specifications.............................................8-1Speedometer ............................................. 3-3
Starting off ................................................. 5-2
Starting the engine .................................... 5-1
Start switch ................................................ 3-6
Steering, checking ................................... 6-21
Storage ...................................................... 7-3
Storage compartments ............................ 3-10
T
Tail/brake light bulb or rear turn signal
light bulb, replacing ............................... 6-27
Throttle cable free play, checking............ 6-14
Throttle grip and cable, checking and
lubricating .............................................. 6-20
Tires ........................................................ 6-14
Tool kit ....................................................... 6-1
Troubleshooting....................................... 6-28
Troubleshooting chart.............................. 6-29
Turn signal indicator light .......................... 3-2
Turn signal light bulb (front), replacing .... 6-26
Turn signal switch...................................... 3-6
V
Valve clearance ....................................... 6-14
Vehicle identification number .................... 9-1
W
Wheel bearings, checking ....................... 6-22
Wheels .................................................... 6-16