2007 YAMAHA CYGNUS 125 maintenance

PERIODIC MAINTENANCE AND MINOR REPAIR
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EAU23271
Checking the front fork
The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic main-
tenance and lubrication chart.
To check the condition
WARNING

EWA10750
Securely support the vehicle so that
there is no danger of it falling over.
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
2. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
CAUTION:

ECA10590
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-
pair it.
EAU23280
Checking the steering
Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the pe-
riodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground.
WARNING

EWA10750
Securely support the vehicle so that
there is no danger of it falling over.
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steering.
ZAUM00**

PERIODIC MAINTENANCE AND MINOR REPAIR
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EAU23290
Checking the wheel bearings
The front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer check
the wheel bearings.
EAUT1853
Battery
This model is equipped with a
sealed-type (MF) battery, which does
not require any maintenance. There is
no need to check the electrolyte or to
add distilled water.
NOTE:

The battery is located behind panel D.
(See page 6-6.)
WARNING

EWA10760

Electrolyte is poisonous and
dangerous since it contains sul-
furic acid, which causes severe
burns. Avoid any contact with
skin, eyes or clothing and al-
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1. Battery
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9ways shield your eyes when
working near batteries. In case
of contact, administer the fol-
lowing FIRST AID.


EXTERNAL: Flush with plenty
of water.

INTERNAL: Drink large quan-
tities of water or milk and im-
mediately call a physician.

EYES: Flush with water for 15
minutes and seek prompt
medical attention.

Batteries produce explosive hy-
drogen gas. Therefore, keep
sparks, flames, cigarettes, etc.,
away from the battery and pro-
vide sufficient ventilation when
charging it in an enclosed
space.

KEEP THIS AND ALL BATTER-
IES OUT OF THE REACH OF
CHILDREN.
To charge the battery
Have a Yamaha dealer charge the bat-
tery as soon as possible if it seems to
have discharged. Keep in mind that the
battery tends to discharge more quicklyif the vehicle is equipped with optional
electrical accessories.
To store the battery
1. If the vehicle will not be used for
more than one month, remove the
battery, fully charge it, and then
place it in a cool, dry place.
2. If the battery will be stored for more
than two months, check it at least
once a month and fully charge it if
necessary.
3. Fully charge the battery before in-
stallation.
4. Before installation, make sure that
the battery leads are properly con-
nected to the battery terminals.
CAUTION:

ECAT1051

Always keep the battery
charged. Storing a discharged
battery can cause permanent
battery damage.

To charge a sealed-type (MF)
battery, a special (constant-volt-
age) battery charger is required.
Using a conventional battery
charger will damage the battery.
If you do not have access to asealed-type (MF) battery charg-
er, have a Yamaha dealer
charge your battery.

After installing the battery, be
sure to turn the main switch
from “ON” to “OFF” three times
in 3 seconds intervals to initial-
ize the idle speed control sys-
tem.

PERIODIC MAINTENANCE AND MINOR REPAIR
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EAUT1914
Replacing the fuses
The main fuse box is located above the
battery.
The fuse box, which contains the fuses
for the individual circuits, is located in
the storage compartment. (See
page 3-10.)If a fuse is blown, replace it as follows.
1. Turn the key to “OFF” and turn off
the electrical circuit in question.
2. Remove the blown fuse, and then
install a new fuse of the specified
amperage.
CAUTION:

ECAT1061

Do not use a fuse of a higher
amperage rating than recom-
mended to avoid causing exten-
sive damage to the electrical
system and possibly a fire.

After removing and installing
the main fuse, be sure to turn
the main switch from “ON” to
“OFF” three times in 3 seconds
intervals to initialize the idle
speed control system.
3. Turn the key to “ON” and turn on
the electrical circuit in question to
check if the device operates.
1. Main fuse
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1. Lid
2. Backup fuse
3. Ignition fuse
4. Signaling system fuse
5. Taillight fuse
6. Headlight fuse
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Specified fuses:
Main fuse:
20.0 A
Headlight fuse:
15.0 A
Signaling system fuse:
15.0 A
Ignition fuse:
7.5 A
Backup fuse:
7.5 A
Taillight fuse:
7.5 A

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4. If the fuse immediately blows
again, have a Yamaha dealer
check the electrical system.

EAUT2130
Replacing the headlight bulb
This model is equipped with a quartz
bulb headlight. If the headlight bulb
burns out, replace it as follows.
1. Place the vehicle on the center-
stand.
2. Remove panel B. (See page 6-6.)
3. Disconnect the headlight coupler,
and then remove the bulb cover.
4. Unhook the headlight bulb holder,
and then remove the defective
bulb.
WARNING

EWA10790
Headlight bulbs get very hot. There-
fore, keep flammable products away
from a lit headlight bulb, and do not
touch the bulb until it has cooled
down.
5. Place a new headlight bulb into po-
sition, and then secure it with the
bulb holder.
CAUTION:

ECA10660
Do not touch the glass part of the
headlight bulb to keep it free from
oil, otherwise the transparency of
the glass, the luminosity of the bulb,
and the bulb life will be adversely af-
1. Bulb cover
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1. Headlight bulb holder
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9 fected. Thoroughly clean off any dirt
and fingerprints on the headlight
bulb using a cloth moistened with al-

cohol or thinner.
6. Install the headlight bulb cover,
and then connect the coupler.
7. Install the panel.
8. Have a Yamaha dealer adjust the
headlight beam if necessary.
EAUT1891
Replacing a front turn signal
light bulb
CAUTION:

ECA10670
It is advisable to have a Yamaha
dealer perform this job.
1. Place the scooter on the center-
stand.
2. Remove panel A. (See page 6-6.)
3. Remove the socket (together with
the bulb) by turning it counter-
clockwise.
4. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.5. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
6. Install the socket (together with the
bulb) by turning it clockwise.
7. Install the panel.
1. Turn signal light bulb
2. Socket
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EAUT1922
Replacing the tail/brake light
bulb or a rear turn signal light
bulb
Tail/brake light bulb
1. Remove the tail/brake light lens by
removing the screws.
2. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.
3. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
4. Install the lens by installing thescrews.
Rear turn signal light bulb
1. Remove the tail/brake light lens by
removing the screws.
2. Remove the turn signal light lens
by removing the screws.
3. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.
4. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
5. Install the turn signal light lens by
installing the screws.
6. Install the tail/brake light lens by in-
stalling the screws.
CAUTION:

ECA10680
Do not overtighten the screws, oth-
erwise the lens may break.
EAUT1962
Replacing an auxiliary light
bulb
This model is equipped with two auxil-
iary lights. If an auxiliary light bulb burns
out, replace it as follows.
1. Remove panel B. (See page 6-6.)
2. Remove the auxiliary light socket
(together with the bulb) by turning
it counterclockwise.
3. Remove the defective bulb by pull-
ing it out.
4. Insert a new bulb into the socket.
5. Install the auxiliary light socket (to-
gether with the bulb) by turning it
clockwise.
1. Tail/brake light lens
2. Turn signal light lens
3. Rear turn signal light bulb
4. Tail/brake light bulb
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1. Auxiliary light bulb
2. Socket
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6. Install the panel.

EAU25860
Troubleshooting
Although Yamaha scooters 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 scooter re-
quire any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the scooter prop-
erly.
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.