YAMAHA CYGNUS 125 2007 Workshop Manual

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WARNING

EWA10470

Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the vehi-
cle with excessively worn tires
decreases riding stability and
can lead to loss of control.

The replacement of all wheel
and brake related parts, includ-
ing the tires, should be left to a
Yamaha dealer, who has the
necessary professional knowl-
edge and experience.
EAU21960
Cast wheels
To maximize the performance, durabil-
ity, and safe operation of your vehicle,
note the following points regarding the
specified wheels.

The wheel rims should be checked
for cracks, bends or warpage be-
fore each ride. If any damage is
found, have a Yamaha dealer re-
place the wheel. Do not attempt
even the smallest repair to the
wheel. A deformed or cracked
wheel must be replaced.

The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced. An
unbalanced wheel can result in
poor performance, adverse han-
dling characteristics, and a short-
ened tire life.

Ride at moderate speeds after
changing a tire since the tire sur-
face must first be “broken in” for it
to develop its optimal characteris-
tics.
EAU22170
Adjusting the rear brake lever
free play
The brake lever free play should mea-
sure 10–20 mm (0.39–0.79 in) as
shown. Periodically check the brake le-
ver free play and, if necessary, adjust it
as follows.
To increase the brake lever free play,
turn the adjusting nut at the brake shoe
plate in direction (a). To decrease the
brake lever free play, turn the adjusting
nut in direction (b).
1. Rear brake lever free play
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WARNING

EWA10650
If proper adjustment cannot be ob-
tained as described, have a Yamaha
dealer make this adjustment.
EAU22380
Checking the front brake pads
and rear brake shoes
The front brake pads and the rear brake
shoes must be checked for wear at the
intervals specified in the periodic main-
tenance and lubrication chart.
EAU22420
Front brake pads
Each front brake pad is provided with a
wear indicator groove, which allows
you to check the brake pad wear with-
out having to disassemble the brake.
To check the brake pad wear, check
the wear indicator groove. If a brake
pad has worn to the point that the wearindicator groove has almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.
EAU22540
Rear brake shoes
The rear brake is provided with a wear
indicator, which allows you to check the
brake shoe wear without having to dis-
assemble the brake. To check the
brake shoe wear, check the position of
the wear indicator while applying the
brake. If a brake shoe has worn to the
point that the wear indicator reaches
the wear limit line, have a Yamaha
dealer replace the brake shoes as a
1. Adjusting nut
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(a)(b)

1. Brake pad wear indicator groove
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1. Wear indicator
2. Wear limit line
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set.

EAU32343
Checking the front brake fluid
level
Insufficient brake fluid may allow air to
enter the brake system, possibly caus-
ing it to become ineffective.
Before riding, check that the brake fluid
is above the minimum level mark and
replenish if necessary. A low brake fluid
level may indicate worn brake pads
and/or brake system leakage. If the
brake fluid level is low, be sure to check
the brake pads for wear and the brake
system for leakage.
Observe these precautions:

When checking the fluid level,
make sure that the top of the mas-ter cylinder is level by turning the
handlebars.

Use only the recommended quality
brake fluid, otherwise the rubber
seals may deteriorate, causing
leakage and poor braking perfor-
mance.

Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking performance.

Be careful that water does not en-
ter the master cylinder when refill-
ing. Water will significantly lower
the boiling point of the fluid and
may result in vapor lock.

Brake fluid may deteriorate paint-
ed surfaces or plastic parts. Al-
ways clean up spilled fluid
immediately.

As the brake pads wear, it is nor-
mal for the brake fluid level to grad-
ually go down. However, if the
brake fluid level goes down sud-
denly, have a Yamaha dealer
1. Minimum level mark
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Recommended brake fluid:
DOT 4

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check the cause.

EAU22720
Changing the brake fluid
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the NOTE after the periodic mainte-
nance and lubrication chart. In addition,
have the oil seals of the brake master
cylinder and caliper as well as the
brake hose replaced at the intervals
listed below or whenever they are dam-
aged or leaking.

Oil seals: Replace every two
years.

Brake hose: Replace every four
years.
EAU23100
Checking and lubricating the
cables
The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING

EWA10720
Damage to the outer sheath may in-
terfere with proper cable operation
and will cause the inner cable to
rust. Replace a damaged cable as
soon as possible to prevent unsafe
conditions.
Recommended lubricant:
Engine oil

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EAU23111
Checking and lubricating the
throttle grip and cable
The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated at
the intervals specified in the periodic
maintenance chart.
EAU23170
Lubricating the front and rear
brake levers
The pivoting points of the front and rear
brake levers must be lubricated at the
intervals specified in the periodic main-
tenance and lubrication chart.
EAU23211
Checking and lubricating the
centerstand and sidestand
The operation of the centerstand and
sidestand should be checked before
each ride, and the pivots and met-
al-to-metal contact surfaces should be
lubricated if necessary.
WARNING

EWA10740
If the centerstand or sidestand does
not move up and down smoothly,
have a Yamaha dealer check or re-
pair it.
Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)
ZAUM00**

Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)
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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.
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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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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.

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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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