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PRE-OPERATION CHECKS
EAU15593
The condition of a vehicle is the owner’s responsibility. Vital components can start to deteriorate quickly and unexpectedly,
even if the vehicle remains unused (for example, as a result of exposure to the elements). Any damage, fluid leakage or loss
of tire air pressure could have serious consequences. Therefore, it is very important, in addition to a thorough visual inspec-
tion, to check the following points before each ride.
NOTE:
Pre-operation checks should be made each time the vehicle is used. Such an inspection can be accomplished in a very short
time; and the added safety it assures is more than worth the time involved.
WARNING
EWA11150
If any item in the Pre-operation check list is not working properly, have it inspected and repaired before operating
the vehicle.
Page 40 of 98
PRE-OPERATION CHECKS
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Wheels and tires
Check for damage.
Check tire condition and tread depth.
Check air pressure.
Correct if necessary.6-22, 6-24
Brake levers
Make sure that operation is smooth.
Lubricate lever pivoting points if necessary.6-29
Centerstand, sidestand
Make sure that operation is smooth.
Lubricate pivots if necessary.6-29
Chassis fasteners
Make sure that all nuts, bolts and screws are properly tightened.
Tighten if necessary.—
Instruments, lights, signals
and switches
Check operation.
Correct if necessary.—
Sidestand switch
Check operation of ignition circuit cut-off system.
If system is defective, have Yamaha dealer check vehicle.3-19
ITEM CHECKS PAGE
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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.
EAU17501
Owner’s tool kit
The owner’s tool kit is located inside the
rear storage compartment. (See
page 3-17.)
Pull up the storage compartment mat,
and then remove the owner’s tool kit.
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.
1. Storage compartment mat
2. Owner’s tool kit
1
2
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EAU1770A
Periodic maintenance and lubrication chart
NOTE:
The annual checks must be performed every year, except if a kilometer-based maintenance, or for the UK, a
mileage-based maintenance, is performed instead.
From 50000 km (30000 mi), repeat the maintenance intervals starting from 10000 km (6000 mi).
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
ANNUAL
CHECK 1000 km
(600 mi)10000 km
(6000 mi)20000 km
(12000 mi)30000 km
(18000 mi)40000 km
(24000 mi)
1*
Fuel line
Check fuel hoses for cracks or
damage.
√√√√√
2
Spark plug
Check condition.
Clean and regap.
√√
Replace.
√√
3*
Valves
Check valve clearance.
Adjust.Every 40000 km (24000 mi)
4
Air filter elements
Replace.
√√
5
V-belt case air filter
element
Clean.
√√√√
6*
Front brake
Check operation, fluid level
and vehicle for fluid leakage.
√√√√√√
Replace brake pads. Whenever worn to the limit
7*
Rear brake
Check operation, fluid level
and vehicle for fluid leakage.
√√√√√√
Replace brake pads. Whenever worn to the limit
8
Rear brake lock
Check operation.
Adjust.
√√√√√√
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EAU34172
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. Open the rider seat. (See
page 3-15.)
2. Pull up the storage compartment
mat, and then remove the spark
plug cover by removing the
screws.3. Remove the spark plug cap.
4. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
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 oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, 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
1. Storage compartment mat
2. Spark plug cover
3. Screw
1. Spark plug cap
1
2
3
1
1. Spark plug wrench
1
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WARNING
EWA14660
Because loading has an enormous
impact on the handling, braking,
performance and safety characteris-
tics of your vehicle, you should keep
the following precautions in mind.
NEVER OVERLOAD THE VEHI-
CLE! Operation of an overload-
ed vehicle may result in tire
damage, loss of control, or se-
vere injury. Make sure that thetotal weight of rider, passenger,
cargo, and accessories does
not exceed the specified maxi-
mum load for the vehicle.
Do not carry along loosely
packed items, which can shift
during a ride.
Securely pack the heaviest
items close to the center of the
vehicle and distribute the
weight evenly on both sides.
Adjust the suspension and tire
air pressure with regard to the
load.
Check the tire condition and air
pressure before each ride.Tire inspection
The tires must be checked before each
ride. If the center tread depth reaches
the specified limit, if the tire has a nail or
glass fragments in it, or if the sidewall is
cracked, have a Yamaha dealer re-
place the tire immediately.
NOTE:
The tire tread depth limits may differ
from country to country. Always comply
with the local regulations.
Tire air pressure (measured on cold
tires):
0–90 kg (0–198 lb):
Front:
200 kPa (29 psi) (2.00 kgf/cm
2
)
Rear:
250 kPa (36 psi) (2.50 kgf/cm
2
)
YP400 90–189 kg (198–417 lb)
YP400A 90–185 kg (198–408 lb):
Front:
200 kPa (29 psi) (2.00 kgf/cm
2
)
Rear:
250 kPa (36 psi) (2.50 kgf/cm
2
)
Maximum load*:
YP400 189 kg (417 lb)
YP400A 185 kg (408 lb)
* Total weight of rider, passenger, car-
go and accessories
1. Tire sidewall
2. Tire tread depth
Minimum tire tread depth (front and
rear):
1.6 mm (0.06 in)
12
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refilling. 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
check the cause.
EAU22730
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 master cylin-
ders and calipers as well as the brake
hoses replaced at the intervals listed
below or whenever they are damaged
or leaking.
Oil seals: Replace every two
years.
Brake hoses: 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
Page 74 of 98
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WARNING
EWA10740
If the centerstand or sidestand does
not move up and down smoothly,
have a Yamaha dealer check or re-
pair it.
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.
Recommended lubricant:
Lithium-soap-based grease