2005 YAMAHA CYGNUS 125 engine

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INSTRUMENT AND CONTROL FUNCTIONS
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.
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PRE-OPERATION CHECKS
ITEM CHECKS PAGE
Fuel Check fuel level in fuel tank.
 Refuel if necessary.
 Check fuel line for leakage.3-6
Engine oil Check oil level in engine.
 If necessary, add recommended oil to specified level.
 Check vehicle for oil leakage.6-8
Final transmission oil Check vehicle for oil leakage. 6-10
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.6-18, 6-19
Rear brake Check operation.
 Lubricate cable if necessary.
 Check lever free play.
 Adjust if necessary.6-18, 6-19
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, 6-21
Wheels and tires Check for damage.
 Check tire condition and tread depth.
 Check air pressure.
 Correct if necessary.6-15, 6-17
Brake levers Make sure that operation is smooth.
 Lubricate lever pivoting points if necessary.6-21
EAU15603
Pre-operation check list
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OPERATION AND IMPORTANT RIDING POINTS
EAU15980
EWA10870
w8 88 8
8Become thoroughly familiar with
all operating controls and their
functions before riding. Consult
a Yamaha dealer regarding any
control or function that you do
not thoroughly understand.
8 88 8
8Never start the engine or operate
it in a closed area for any length
of time. Exhaust fumes are poi-
sonous, and inhaling them can
cause loss of consciousness and
death within a short time. Always
make sure that there is adequate
ventilation.
8 88 8
8For safety, always start the engine
with the centerstand down.EAU15940
OPERATION AND IMPORTANT RIDING POINTS
EAUT1100
Starting a cold engine
ECA10250
cCSee page 5-3 for engine break-in in-
structions prior to operating the ve-
hicle for the first time.1. Turn the key to “ON”.
2. Close the throttle grip completely.
3. Start the engine by pushing the
star t switch or by kicking the
kickstarter, while applying the front
or rear brake.NOTE:
If the engine fails to start by pushing
the start switch, release the switch, wait
a few seconds, and then try again. Each
starting attempt should be as short as
possible to preserve the battery. Do not
crank the engine more than 5 seconds
on any one attempt. If the engine does
not start with the starter motor, try us-
ing the kickstarter.
ECA11040
cCFor maximum engine life, never ac-
celerate hard when the engine is cold!
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OPERATION AND IMPORTANT RIDING POINTS
EAU16780
Acceleration and decelerationZAUM00**
(a)(b)
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 throttle
grip in direction (b).
EAU16760
Starting offNOTE:
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.
EAU16791
Braking1. Close the throttle completely.
2. Apply both front and rear brakes si-
multaneously while gradually in-
creasing the pressure.
EWA10300
w8 88 8
8Avoid braking hard or suddenly
(especially when leaning over to
one side), otherwise the scooter
may skid or overturn.
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8Railroad crossings, streetcar
rails, iron plates on road con-
struction sites, and manhole cov-
ers become extremely slippery
when wet. Therefore, slow down
when approaching such areas
and cross them with caution.
8 88 8
8Keep in mind that braking on a
wet road is much more difficult.
8 88 8
8Ride slowly down a hill, as brak-
ing downhill can be very difficult.
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OPERATION AND IMPORTANT RIDING POINTS
EAU16830
Engine break-inThere 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. Dur-
ing this period, prolonged full-throttle
operation or any condition that might
result in engine overheating must be
avoided.
EAU16820
Tips for reducing fuel con-
sumptionFuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:
8Avoid high engine speeds during
acceleration.
8Avoid high engine speeds with no
load on the engine.
8Turn 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).
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.
ECA10350
cCAfter 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.
ECA10270
cCIf any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.
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OPERATION AND IMPORTANT RIDING POINTS
EAU17212
ParkingWhen parking, stop the engine, and then
remove the key from the main switch.
EWA10310
w8 88 8
8Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them.
8 88 8
8Do not park on a slope or on soft
ground, otherwise the vehicle
may overturn.
ECA10380
cCNever park in an area where there are
fire hazards such as grass or other
flammable materials.
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PERIODIC MAINTENANCE AND MINOR REPAIR9
*Wheels Check runout and for damage.————
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
assembly Check operation and shock absorber for oil leakage.————
18*Carburetor Adjust engine idling speed.————— —
19*Engine oil Change. (see page 3-2)—Every 3000 km
 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.————— — NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (u1,000 km)
ANNUAL
CHECK
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAUT1170
Checking the spark plugThe 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 char t. 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 included
in the owner’s tool kit.ZAUM00**1
1. Spark plug wrench
To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).NOTE:
If the spark plug shows a distinctly dif-
ferent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself. Instead, have a
Yamaha dealer check the vehicle.2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if nec-
essary.
Specified spark plug:
CR7E (NGK)
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
ZAUM00**
12(×4)
1. Panel B
2. ScrewTo install the panel
Place the panel in the original position,
and then install the screws.
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