engine YAMAHA CYGNUS 125 2007 User Guide

INSTRUMENT AND CONTROL FUNCTIONS
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EAU13441
Catalytic converter
This vehicle is equipped with catalytic
converters in the exhaust system.
WARNING

EWA10860
The exhaust system is hot after op-
eration. Make sure that the exhaust
system has cooled down before do-
ing any maintenance work.
CAUTION:

ECA10700
The following precautions must be
observed to prevent a fire hazard or
other damages.

Use only unleaded gasoline.
The use of leaded gasoline will
cause unrepairable damage to
the catalytic converter.

Never park the vehicle near pos-
sible fire hazards such as grass
or other materials that easily
burn.

Do not allow the engine to idle
too long.
EAU13680
Kickstarter
To start the engine, fold out the kick-
starter lever, move it down lightly with
your foot until the gears engage, and
then push it down smoothly but force-
fully.
EAUT1502
Seat
To open the seat
1. Place the scooter on the center-
stand.
2. Insert the key into the main switch,
and then turn it counterclockwise
to the first “OPEN” position. If the
main switch is in the “LOCK” posi-
tion, turn the key counterclockwise
to the second “OPEN” position.
NOTE:

Do not push inward when turning the
key from “OFF” to “OPEN” or from
“LOCK” to “OPEN”.
3. Fold the seat up.
1. Kickstarter
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INSTRUMENT AND CONTROL FUNCTIONS
3-12
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EAUT1091
Sidestand switch operation
check
Check the operation of the sidestand
switch against the information below.
WARNING

EWA10260

The vehicle must be placed on
the centerstand during this in-
spection.

If a malfunction is noted, have a
Yamaha dealer check the sys-
tem before riding.
Turn the key on.
Put the sidestand up.Push the start switch while applying
either of the brake levers. The engine will
start.Put the sidestand down.
If the engine stalls:
The sidestand switch is OK.

PRE-OPERATION CHECKS
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EAU15605
Pre-operation check list
ITEM CHECKS PAGE
Fuel

Check fuel level in fuel tank.

Refuel if necessary.

Check fuel line for leakage.3-8
Engine oil

Check oil level in engine.

If necessary, add recommended oil to specified level.

Check vehicle for oil leakage.6-9
Final transmission oil

Check vehicle for oil leakage. 6-11
Front brake

Check operation.

If soft or spongy, have Yamaha dealer bleed hydraulic system.

Check brake pads for wear.

Replace if necessary.

Check fluid level in reservoir.

If necessary, add recommended brake fluid to specified level.

Check hydraulic system for leakage.6-17, 6-18
Rear brake

Check operation.

Lubricate cable if necessary.

Check lever free play.

Adjust if necessary.6-16, 6-17
Throttle grip

Make sure that operation is smooth.

Check cable free play.

If necessary, have Yamaha dealer adjust cable free play and lubricate cable
and grip housing.6-14, 6-20
Wheels and tires

Check for damage.

Check tire condition and tread depth.

Check air pressure.

Correct if necessary.6-14, 6-16
Brake levers

Make sure that operation is smooth.

Lubricate lever pivoting points if necessary.6-20

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OPERATION AND IMPORTANT RIDING POINTS
EAU15980
WARNING

EWA10870

Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer re-
garding any control or function
that you do not thoroughly un-
derstand.

Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.

For safety, always start the en-
gine with the centerstand down.
EAUT1861
Starting the engine
CAUTION:

ECA10250
See page 5-3 for engine break-in in-
structions prior to operating the ve-
hicle for the first time.
In order for the ignition circuit cut-off
system to enable starting, the side-
stand must be up.
WARNING

EWA10290

Before starting the engine,
check the function of the igni-
tion circuit cut-off system ac-
cording to the procedure
described on page 3-12.

Never ride with the sidestand
down.
1. Turn the key to “ON”.
CAUTION:

ECAT1040
The engine trouble warning light
should come on for a few seconds,
then go off. If the warning light does
not go off, have a Yamaha dealer
check the electrical circuit.
2. Close the throttle completely.3. Start the engine by pushing the
start switch while applying the front
or rear brake.
NOTE:

If the engine does not start, release the
start switch, wait a few seconds, and
then try again. Each starting attempt
should be as short as possible to pre-
serve the battery. Do not crank the en-
gine more than 5 seconds on any one
attempt. If the engine does not start
with the starter motor, try using the
kickstarter.
CAUTION:

ECA11040
For maximum engine life, never ac-
celerate hard when the engine is
cold!

OPERATION AND IMPORTANT RIDING POINTS
5-2
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9

EAU16760
Starting off
NOTE:

Before starting off, allow the engine to
warm up.
1. While pulling the rear brake lever
with your left hand and holding the
grab bar with your right hand, push
the scooter off the centerstand.
2. Sit astride the seat, and then ad-
just the rear view mirrors.
3. Switch the turn signal on.
4. Check for oncoming traffic, and
then slowly turn the throttle grip (on
the right) in order to take off.
5. Switch the turn signal off.
EAU16780
Acceleration and deceleration
The speed can be adjusted by opening
and closing the throttle. To increase the
speed, turn the throttle grip in direction
(a). To reduce the speed, turn the throt-
tle grip in direction (b).
EAU16791
Braking
1. Close the throttle completely.
2. Apply both front and rear brakes
simultaneously while gradually in-
creasing the pressure.
WARNING

EWA10300

Avoid braking hard or suddenly
(especially when leaning over to
one side), otherwise the scooter
may skid or overturn.

Railroad crossings, streetcar
rails, iron plates on road con-
struction sites, and manhole
covers become extremely slip-
pery when wet. Therefore, slow
down when approaching such
areas and cross them with cau-
tion.

Keep in mind that braking on a
wet road is much more difficult.

Ride slowly down a hill, as brak-
ing downhill can be very diffi-
cult.
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(a)(b)

OPERATION AND IMPORTANT RIDING POINTS
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EAU16820
Tips for reducing fuel
consumption
Fuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:

Avoid high engine speeds during
acceleration.

Avoid high engine speeds with no
load on the engine.

Turn the engine off instead of let-
ting it idle for an extended length of
time (e.g., in traffic jams, at traffic
lights or at railroad crossings).
EAU16830
Engine break-in
There is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the follow-
ing material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that might
result in engine overheating must be
avoided.
EAU16950
0–150 km (0–90 mi)
Avoid prolonged operation above 1/3
throttle.
After every hour of operation, stop the
engine, and then let it cool for five to ten
minutes.
Vary the engine speed from time to
time. Do not operate the engine at one
set throttle position.
150–500 km (90–300 mi)
Avoid prolonged operation above 1/2
throttle.
Rev the engine freely through the
gears, but do not use full throttle at any
time.
500–1000 km (300–600 mi)
Avoid prolonged operation above 3/4
throttle.
CAUTION:

ECA10350
After 1000 km (600 mi) of operation,
the engine oil must be changed and
the oil strainer cleaned.
1000 km (600 mi) and beyond
Avoid prolonged full-throttle operation.
Vary the speed occasionally.
CAUTION:

ECA10270
If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.

OPERATION AND IMPORTANT RIDING POINTS
5-4
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9

EAU17212
Parking
When parking, stop the engine, and
then remove the key from the main
switch.
WARNING

EWA10310

Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them.

Do not park on a slope or on soft
ground, otherwise the vehicle
may overturn.
CAUTION:

ECA10380
Never park in an area where there
are fire hazards such as grass or
other flammable materials.

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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU17280
Safety is an obligation of the owner. Pe-
riodic inspection, adjustment and lubri-
cation will keep your vehicle in the
safest and most efficient condition pos-
sible. The most important points of in-
spection, adjustment, and lubrication
are explained on the following pages.
The intervals given in the periodic
maintenance and lubrication chart
should be simply considered as a gen-
eral guide under normal riding condi-
tions. However, DEPENDING ON THE
WEATHER, TERRAIN, GEOGRAPHI-
CAL LOCATION, AND INDIVIDUAL
USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORT-
ENED.
WARNING

EWA10320
If you are not familiar with mainte-
nance work, have a Yamaha dealer
do it for you.
WARNING

EWA10330
This scooter is designed for use on
paved roads only. If this scooter isoperated in abnormally dusty, mud-
dy or wet conditions, the air filter el-
ement should be cleaned or
replaced more frequently, otherwise
rapid engine wear may result. Con-
sult a Yamaha dealer for proper
maintenance intervals.
EAU17520
Owner’s tool kit
The owner’s tool kit is located inside the
storage compartment under the seat.
(See page 3-9.)
The service information included in this
manual and the tools provided in the
owner’s tool kit are intended to assist
you in the performance of preventive
maintenance and minor repairs. How-
ever, additional tools such as a torque
wrench may be necessary to perform
certain maintenance work correctly.
NOTE:

If you do not have the tools or experi-
ence required for a particular job, have
1. Owner’s tool kit
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-4
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8
9

10

*
Tires

Check tread depth and for damage.

Replace if necessary.

Check air pressure.

Correct if necessary.
√√√√ √
11

*
Wheel bearings

Check bearing for looseness or damage.
√√√√
12

*
Steering bearings

Check bearing play and steering for roughness.
√√√√√

Lubricate with lithium-soap-based grease. Every 24000 km
13

*
Chassis fasteners

Make sure that all nuts, bolts and screws are properly
tightened.
√√√√ √
14

Sidestand, centerstand

Check operation.

Lubricate.
√√√√ √
15

*
Sidestand switch

Check operation.
√√√√√ √
16

*
Front fork

Check operation and for oil leakage.
√√√√
17

*
Shock absorber assem-
bly

Check operation and shock absorber for oil leakage.
√√√√
18

*
Fuel injection

Check engine idle speed.
√√√√√ √
19

Engine oil

Change. (See page 6-9.)

Check oil level and vehicle for oil leakage.
√
Every 3000 km
20

*
Engine oil strainer

Clean.
√
21

Final transmission oil

Check vehicle for oil leakage.
√√ √

Change.
√√√
22

*
V-belt

Replace. Every 18000 km
23

*
Front and rear brake
switches

Check operation.
√√√√√ √
24

Moving parts and cables

Lubricate.
√√√√ √
25

*
Throttle grip housing
and cable

Check operation and free play.

Adjust the throttle cable free play if necessary.

Lubricate the throttle grip housing and cable.
√√√√ √
NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (
×
1000 km)
ANNUAL
CHECK
1 6 12 18 24

PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
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To install the panel
Place the panel in the original position,
and then install the screws.
Panel D
To remove the panel1. Open the seat. (See page 3-9.)2. Remove the quick fasteners by
pushing in the center pin, and then
take the panel off.
To install the panel
Place the panel in the original position,
and then install quick fasteners.

EAUT1830
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Remove panel C. (See page 6-6.)
2. Remove the spark plug cap.
3. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
1. Panel C
2. Screw
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1. Panel D
2. Screw
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1. Spark plug wrench
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