2007 YAMAHA CYGNUS 125 fuel

INSTRUMENT AND CONTROL FUNCTIONS
3-8
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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)

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

OPERATION AND IMPORTANT RIDING POINTS
5-3
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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.

PERIODIC MAINTENANCE AND MINOR REPAIR
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EAU17710
Periodic maintenance and lubrication chart
NOTE:


The annual checks must be performed every year, except if a kilometer-based maintenance is performed in-
stead.

From 30000 km, repeat the maintenance intervals starting from 6000 km.

Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technical
skills.
NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (
×
1000 km)
ANNUAL
CHECK
1 6 12 18 24
1*
Fuel line


Check fuel and vacuum hoses for cracks or damage.
√√√√ √
2
Spark plug

Check condition.

Clean and regap.
√√

Replace.
√√
3*
Valves

Check valve clearance.

Adjust.
√√√√
4
Air filter element

Clean.
√√

Replace.
√√
5
V-belt case air filter ele-
ment

Clean.
√√√√
6*
Front brake

Check operation, fluid level and vehicle for fluid leak-
age.
√√√√√ √

Replace brake pads. Whenever worn to the limit
7*
Rear brake

Check operation and adjust brake lever free play.
√√√√√ √

Replace brake shoes. Whenever worn to the limit
8*
Brake hose

Check for cracks or damage.
√√√√ √

Replace. Every 4 years
9*
Wheels

Check runout and for damage.
√√√√

PERIODIC MAINTENANCE AND MINOR REPAIR
6-4
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67
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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
6-14
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3
4
5
67
8
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EAU21382
Checking the throttle cable
free play
The throttle cable free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, have a Yamaha dealer adjust it.
EAU21401
Valve clearance
The valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAUT2140
Tires
To maximize the performance, durabil-
ity, and safe operation of your vehicle,
note the following points regarding the
specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING

EWA10500

The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).

The tire air pressure must be ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
1. Throttle cable free play
ZAUM00**
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-28
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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.

PERIODIC MAINTENANCE AND MINOR REPAIR
6-29
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EAUT1980
Troubleshooting chart
WARNING

EWA10840
Keep 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
Operate the electric starter.