YAMAHA CYGNUS 125 2005 Repair Manual

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PERIODIC MAINTENANCE AND MINOR REPAIR
the bulb life will be adversely affected.
Thoroughly clean off any dirt and fin-
gerprints on the headlight bulb us-
ing a cloth moistened with alcohol
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.
EAU24131
Replacing the tail/brake light
bulb1. Remove the tail/brake light lens by
removing the screws.
2. Remove the defective bulb by push-
ing it in and turning it counterclock-
wise.ZAUM00**
1
1. Bulb3. 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 the
screws.
ECA10680
cCDo not overtighten the screws, other-
wise the lens may break.
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAUT1360
Replacing a front turn signal
light bulb
ECA10670
cCIt is advisable to have a Yamaha dealer
perform this job.1. Place the scooter on the
centerstand.
2. Remove panel A. (See page 6-6.)
3. Remove the socket (together with
the bulb) by turning it counterclock-
wise.
4. Remove the defective bulb by push-
ing it in and turning it counterclock-
wise.ZAUM00**
2 1
1. Socket
2. Turn signal light bulb
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.
EAUT1330
Rear turn signal light bulbIf a rear turn signal light does not come
on, have a Yamaha dealer check the
electrical circuit or replace the bulb.
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU25860
TroubleshootingAlthough 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 rep-
resents a quick and easy procedure for
checking these vital systems yourself.
However, should your scooter require any
repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary
tools, experience, and know-how to ser-
vice the scooter properly.
Use only genuine Yamaha replacement
parts. Imitation parts may look like
Yamaha parts, but they are often infe-
rior, have a shorter service life and can
lead to expensive repair bills.
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU25901
Troubleshooting chart
EWA10840
wKeep 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.
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SCOOTER CARE AND STORAGE
EAU26090
CareWhile the open design of a scooter re-
veals the attractiveness of the technol-
ogy, it also makes it more vulnerable.
Rust and corrosion can develop even if
high-quality components are used. A
rusty exhaust pipe may go unnoticed on
a car, however, it detracts from the over-
all appearance of a scooter. Frequent and
proper care does not only comply with
the terms of the warranty, but it will also
keep your scooter looking good, extend
its life and optimize its performance.
Before cleaning
1. Cover the muffler outlet with a plas-
tic bag after the engine has cooled
down.
2. Make sure that all caps and cov-
ers as well as all electrical couplers
and connectors, including the spark
plug cap, are tightly installed.
3. Remove extremely stubborn dirt,
like oil burnt onto the crankcase,
with a degreasing agent and a
brush, but never apply such prod-ucts onto seals, gaskets and wheel
axles. Always rinse the dirt and
degreaser off with water.
Cleaning
ECA10780
cC8 88 8
8Avoid using strong acidic wheel
cleaners, especially on spoked
wheels. If such products are used
on hard-to-remove dirt, do not
leave the cleaner on the affected
area any longer than instructed.
Also, thoroughly rinse the area
off with water, immediately dry
it, and then apply a corrosion
protection spray.
8 88 8
8Improper cleaning can damage
windshields, cowlings, panels
and other plastic parts. Use only
a soft, clean cloth or sponge with
mild detergent and water to clean
plastic.
8 88 8
8Do not use any harsh chemical
products on plastic parts. Be sure
to avoid using cloths or sponges
which have been in contact with
strong or abrasive cleaning prod-ucts, solvent or thinner, fuel
(gasoline), rust removers or in-
hibitors, brake fluid, antifreeze or
electrolyte.
8 88 8
8Do not use high-pressure wash-
ers or steam-jet cleaners since
they cause water seepage and
deterioration in the following ar-
eas: seals (of wheel and
swingarm bearings, fork and
brakes), electric components
(couplers, connectors, instru-
ments, switches and lights),
breather hoses and vents.
8 88 8
8For scooters equipped with a
windshield: Do not use strong
cleaners or hard sponges as they
will cause dulling or scratching.
Some cleaning compounds for
plastic may leave scratches on
the windshield. Test the product
on a small hidden part of the
windshield to make sure that it
does not leave any marks. If the
windshield is scratched, use a
quality plastic polishing com-
pound after washing.
EAU25990
SCOOTER CARE AND STORAGE
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SCOOTER CARE AND STORAGEAfter normal use
Remove dirt with warm water, a mild
detergent, and a soft, clean sponge, and
then rinse thoroughly with clean water.
Use a toothbrush or bottlebrush for hard-
to-reach areas. Stubborn dirt and insects
will come off more easily if the area is
covered with a wet cloth for a few min-
utes before cleaning.After riding in the rain, near the sea oron salt-sprayed roads
Since sea salt or salt sprayed on the
roads during winter are extremely corro-
sive in combination with water, carry out
the following steps after each ride in the
rain, near the sea or on salt-sprayed
roads.NOTE:
Salt sprayed on roads in the winter may
remain well into spring.1. Clean the scooter with cold water
and a mild detergent after the en-
gine has cooled down.
ECA10790
cCDo not use warm water since it in-
creases the corrosive action of the
salt.2. Apply a corrosion protection spray
on all metal, including chrome- and
nickel-plated, surfaces to prevent
corrosion.
After cleaning
1. Dry the scooter with a chamois or
an absorbing cloth.
2. Use a chrome polish to shine
chrome, aluminum and stainless-
steel parts, including the exhaust
system. (Even the thermally in-
duced discoloring of stainless-steel
exhaust systems can be removed
through polishing.)
3. To prevent corrosion, it is recom-
mended to apply a corrosion pro-
tection spray on all metal, includ-
ing chrome- and nickel-plated, sur-
faces.
4. Use spray oil as a universal cleaner
to remove any remaining dirt.5. Touch up minor paint damage
caused by stones, etc.
6. Wax all painted surfaces.
7. Let the scooter dry completely be-
fore storing or covering it.
EWA10940
w8 88 8
8Make sure that there is no oil or
wax on the brakes or tires. If nec-
essary, clean the brake discs and
brake linings with a regular brake
disc cleaner or acetone, and
wash the tires with warm water
and a mild detergent.
8 88 8
8Before operating the scooter test
its braking performance and cor-
nering behavior.
ECA10800
cC8 88 8
8Apply spray oil and wax spar-
ingly and make sure to wipe off
any excess.
8 88 8
8Never apply oil or wax to any rub-
ber and plastic parts, but treat
them with a suitable care prod-
uct.
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SCOOTER CARE AND STORAGE
8 88 8
8Avoid using abrasive polishing
compounds as they will wear
away the paint.NOTE:
Consult a Yamaha dealer for advice on
what products to use.
EAU26300
StorageShort-term
Always store your scooter in a cool, dry
place and, if necessary, protect it
against dust with a porous cover.
ECA10820
cC8 88 8
8Storing the scooter 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.
8 88 8
8To prevent corrosion, avoid
damp cellars, stables (because of
the presence of ammonia) and
areas where strong chemicals are
stored.Long-term
Before storing your scooter for several
months:
1. Follow all the instructions in the
“Care” section of this chapter.
2. Drain the carburetor float chamber
by loosening the drain bolt; this will
prevent fuel deposits from building
up. Pour the drained fuel into the
fuel tank.3. Fill up the fuel tank and add fuel
stabilizer (if available) to prevent the
fuel tank from rusting and the fuel
from deteriorating.
4. 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.
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SCOOTER CARE AND STORAGE
EWA10950
wTo prevent damage or injury from
sparking, make sure to ground the
spark plug electrodes while turning
the engine over.5. Lubricate all control cables and the
pivoting points of all levers and
pedals as well as of the sidestand/
centerstand.
6. 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.
7. Cover the muffler outlet with a plas-
tic bag to prevent moisture from en-
tering it.
8. 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 excessively 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 6-23.
NOTE:
Make any necessary repairs before stor-
ing the scooter.
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SPECIFICATIONS
-20˚ -10˚ 0˚ 10˚ 20˚ 30˚ 40˚ 50˚
SAE 10W-30SAE 10W-40
SAE 20W-40SAE 20W-50
ZAUM00**
EAU26320
SPECIFICATIONS
EAU26339
DimensionsOverall length
1855 mm
Overall width
685 mm
Overall height
1110 mm
Seat height
770 mm
Wheelbase
1295 mm
Ground clearance
110 mm
Minimum turning radius
1900 mmWeightWith oil and fuel
121.0 kgEngineEngine type
Forced air cooled 4-stroke, SOHC
Cylinder arrangement
Forward-inclined single cylinder
Displacement
124.0 cm
3
Bore & stroke
52.4 x 57.9 mm
Compression ratio
10.00 :1
Starting system
Electric starter and kickstarter
Lubrication system
Wet sump
Engine oilType
SAE20W40
Recommended engine oil grade
API service SE, SF, SG type or higher
Engine oil quantity
Periodic oil change
0.90 L
Without oil filter element removal
0.90 LFinal transmission oilType
SAE10W30 type SE motor oil
Quantity
0.13 LAir filterAir filter element
Oil-coated paper elementFuelRecommended fuel
Regular unleaded gasoline only
Fuel tank capacity
7.1 L
CarburetorManufacturer
Taiwan KEI HIN
Type x quantity
CVK24 x 1Spark plug(s)Manufacturer/model
NGK / CR7E
Spark plug gap
0.6-0.7 mmClutchClutch type
Dry, centrifugal automaticTransmissionPrimary 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 typeChassisFrame type
Steel tube underbone
Caster angle
27.00 degree
Trail
90.0 mm
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SPECIFICATIONSFront tireType
Tubeless
Size
110 / 70-12 47L
Manufacturer/model
CHENG SHIN / C-922N-47LRear tireType
Tubeless
Size
120 / 70-12 58L
Manufacturer/model
CHENG SHIN / C-6007-58L
Maximum load
170 kg
(Total weight of rider, passenger, cargo and ac-
cessories)Tire air pressure (measured on cold tires)Loading condition
0-90 kg
Front
175 kPa
Rear
200 kPa
Loading condition
90-170 kg
Front
200 kPa
Rear
225 kPaFront wheelWheel type
Cast wheel
Rim size
12xMT2.75
Rear wheelWheel type
Cast wheel
Rim size
12xMT3.00Front brakeType
Single disc brake
Operation
Right hand operation
Recommended fluid
DOT 4Rear brakeType
Drum brake
Operation
Left hand operationFront suspensionType
Telescopic fork
Spring/shock absorber type
Coil spring/oil damper
Wheel travel
90.0 mmRear suspensionType
Unit swing
Spring/shock absorber type
Coil spring/oil damper
Wheel travel
95.0 mm
Electrical systemIgnition system
C.D.I.
Charging system
A.C. magnetoBatteryModel
YTX7A-BS
Voltage, capacity
12 V, 6.0 AhHeadlightBulb type
Halogen bulbBulb voltage, wattage x quantityHeadlight
12 V, 60 W/55.0 W x 1
Tail/brake light
12 V, 5.0/21.0 W x 1
Front turn signal light
12 V, 10.0 W x 2
Rear turn signal light
12 V, 16.0 W x 2
Auxiliary light
12 V, 5.0 W x 1
Meter lighting
12 V, 1.7 W x 3
High beam indicator light
12 V, 1.7 W x 1
Turn signal indicator light
12 V, 3.4 W x 1
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