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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. 
EAU21871 
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.
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 the 
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 
         
        
        
     
        
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9 total 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 information  
This model is equipped with tubeless
tires.
WARNING
 
EWA10470 
 
Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the vehi-
cle with excessively worn tires
decreases riding stability and
can lead to loss of control. 
 
The replacement of all wheel
and brake related parts, includ-
ing the tires, should be left to a
Yamaha dealer, who has the
necessary professional knowl- 
1. Tire sidewall
2. Tire tread depth 
Minimum tire tread depth (front and 
rear): 
1.6 mm (0.06 in)
12
 
Front tire:  
Size:
120/80-14M/C 58S
Manufacturer/model:
IRC/MB67
DUNLOP/D305FL  
Rear tire:  
Size:
150/70-13M/C 64S
Manufacturer/model:
IRC/MB67
DUNLOP/D305L 
         
        
        
     
        
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EAU33453 
Front and rear brake lever free 
play  
Front
Rear 
There should be no free play at the
brake lever ends. If there is free play,
have a Yamaha dealer inspect thebrake system.
WARNING
 
EWA14211 
A soft or spongy feeling in the brake
lever can indicate the presence of air
in the hydraulic system. If there is air
in the hydraulic system, have a
Yamaha dealer bleed the system be-
fore operating the vehicle. Air in the
hydraulic system will diminish the
braking performance, which may re-
sult in loss of control and an acci- 
dent. 
EAU33473 
Adjusting the rear brake lock 
lever cable  
Rear brake lock lever cable adjustment
may be required if the rear brake lock
lever does not hold properly. When the
rear brake lock lever is not in use, the
rear brake lock lever cable length
should measure 45 mm to 47 mm (1.77
in to 1.85 in) at the rear brake caliper.
Periodically check the rear brake lock
lever cable length and, if necessary,
adjust it as follows.
To increase the rear brake lock lever
cable length, turn the adjusting nut at
the rear brake caliper in direction (a). 
1. Adjusting nut
2. Rear brake lock lever cable length
1
2
(a) (b) 
         
        
        
     
        
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To decrease the rear brake lock lever
cable length, turn the adjusting nut in
direction (b).
WARNING
 
EWA10650 
If proper adjustment cannot be ob-
tained as described, have a Yamaha 
dealer make this adjustment. 
EAU22390 
Checking the front and rear 
brake pads  
The front and rear brake pads must be
checked for wear at the intervals spec-
ified in the periodic maintenance and
lubrication chart. 
EAU22430 
Front brake pads 
Each front brake pad is provided with
wear indicator grooves, which allow
you to check the brake pad wear with-
out having to disassemble the brake.
To check the brake pad wear, check
the wear indicator grooves. If a brake
pad has worn to the point that the wearindicator grooves have almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set. 
EAU34210 
Rear brake pads  
Have a Yamaha dealer check each
rear brake pad for damage and mea-
sure the lining thickness and if neces-
sary, replace them as a set. 
1. Wear indicator groove
11 
         
        
        
     
        
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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. 
EAU23111 
Checking and lubricating the 
throttle grip and cable  
The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated at
the intervals specified in the periodic
maintenance chart. 
Recommended lubricant: 
Engine oil 
         
        
        
     
        
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EAU23170 
Lubricating the front and rear 
brake levers  
The pivoting points of the front and rear
brake levers must be lubricated at the
intervals specified in the periodic main-
tenance and lubrication chart. 
EAU23211 
Checking and lubricating the 
centerstand and sidestand  
The operation of the centerstand and
sidestand should be checked before
each ride, and the pivots and met-
al-to-metal contact surfaces should be
lubricated if necessary.
WARNING
 
EWA10740 
If the centerstand or sidestand does
not move up and down smoothly,
have a Yamaha dealer check or re- 
pair it. 
Recommended lubricant: 
Lithium-soap-based grease (all-pur-
pose grease) 
Recommended lubricant:  
Lithium-soap-based grease (all-pur-
pose grease) 
         
        
        
     
        
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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. 
EAU23280 
Checking the steering  
Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the pe-
riodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground.
WARNING
 
EWA10750 
Securely support the vehicle so that 
there is no danger of it falling over.  
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steering. 
         
        
        
     
        
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EAU23290 
Checking the wheel bearings  
The front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer check
the wheel bearings. 
EAU34221 
Battery  
The battery is located behind cowling
A. (See page 6-6.)
This model is equipped with a
sealed-type (MF) battery, which does
not require any maintenance. There is
no need to check the electrolyte or to
add distilled water.
WARNING
 
EWA10760 
 
Electrolyte is poisonous and
dangerous since it contains sul-
furic acid, which causes severe
burns. Avoid any contact with
skin, eyes or clothing and al-
ways shield your eyes when 
1. Battery
1