2021 YAMAHA NMAX 155 service

Periodic maintenance an d a djustment
9-1
9
EAU17246
Periodic inspection, adjustment, and
lubrication will keep your vehicle in the
safest and most efficient condition
possible. Safety is an obligation of the
vehicle owner/operator. The most im-
portant points of vehicle inspection,
adjustment, and lubrication are ex-
plained on the following pages.
The intervals given in the periodic
maintenance charts should be simply
considered as a general guide under
normal riding conditions. However, de-
pending on the weather, terrain, geo-
graphical location, and individual use,
the maintenance intervals may need to
be shortened.
WARNING
EWA10322
Failure to properly maintain the vehi-
cle or performin g maintenance ac-
tivities incorrectly may increase
your risk of injury or death durin g
service or while usin g the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha d ealer perform
service.
WARNING
EWA15123
Turn off the en gine when performin g
maintenance unless otherwise
specified .
 A runnin g en gine has movin g
parts that can catch on body
parts or clothin g an d electrical
parts that can cause shocks or
fires.
 Runnin g the en gine while ser-
vicin g can lead to eye injury,
b urns, fire, or car bon monoxi de
poisonin g – possi bly lea din g to
d eath. See pag e 1-3 for more in-
formation a bout car bon monox-
i d e.
WARNING
EWA15461
Brake discs, calipers, drums, and
linin gs can b ecome very hot d uring
use. To avoi d possi ble burns, let
b rake components cool before
touchin g them.
EAU85230
Tool kitThe tool kit is in the location shown.
The information included in this manual
and the tools provided in the tool kit are
intended to assist you in the perfor-
mance of preventive maintenance and
minor repairs. However, a torque
wrench and other tools are necessary
to perform certain maintenance work
correctly.TIPIf you do not have the tools or experi-
ence required for a particular job, have
your Yamaha dealer perform it for you.1. Tool kit
1
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Periodic maintenance an d a djustment
9-6
9
EAU72790
TIP Engine air filter and V-belt air filter
• This model’s engine air filter is equipped with a disposable oil-coated paper element, which must not be cleaned with compressed air to avoid damaging it.
• The engine air filter element needs to be replaced and the V-belt air filter element needs to be serviced more fre-
quently when riding in unusually wet or dusty areas.
 Hydraulic brake service
• After disassembling the brake master cylinders and calipers, always change the fluid. Regularly check the brake fluid levels and fill the reservoirs as required.
• Every two years replace the internal components of the brake master cylinders and calipers, and change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.
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Periodic maintenance an d a djustment
9-16
9
a
dde d to the coolant, have a
Yamaha dealer check the anti-
freeze content of the coolant as
soon as possi ble, otherwise the
effectiveness of the coolant will
b e re duce d.
[ECA10473]
6. Install the coolant reservoir cover.
7. Place the right floorboard mat in
the original position and push it
downward to secure it.
EAU33032
Chan gin g the coolant
The coolant must be changed at the in-
tervals specified in the periodic main-
tenance and lubrication chart. Have a
Yamaha dealer change the coolant.
WARNING! Never attempt to remove
the ra diator cap when the en gine is
hot.
[EWA10382] EAU67174
Air filter an
d V- belt case air fil-
ter elementsThe air filter element should be re-
placed and the V-belt case air filter el-
ement should be cleaned at the
intervals specified in the periodic main-
tenance and lubrication chart. Service
the air filter elements more frequently if
you are riding in unusually wet or dusty
areas. The air filter check hose and V-
belt case air filter check hose must be
frequently checked and cleaned if nec-
essary.
Cleanin g the air filter check hose
1. Coolant reservoir capCoolant reservoir capacity (up to
the maximum level mark):
0.13 L (0.14 US qt, 0.11 Imp.qt)
1
1. Air filter check hose
1
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Periodic maintenance an d a djustment
9-19
9
EAU21386
Checkin g the throttle grip free
playMeasure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
EAU21403
Valve clearanceThe valves are an important engine
component, and since valve clearance
changes with use, they must be
checked and adjusted at the intervals
specified in the periodic maintenance
chart. Unadjusted valves can result in
improper air-fuel mixture, engine
noise, and eventually engine damage.
To prevent this from occurring, have
your Yamaha dealer check and adjust
the valve clearance at regular intervals.TIPThis service must be performed when
the engine is cold.
EAU69761
TiresTires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
WARNING
EWA10504
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control.  The tire air pressure must be
checked and a djuste d on col d
tires (i.e., when the temperature
of the tires equals the am bient
temperature).
 The tire air pressure must be
a d juste d in accor dance with the
ri din g speed and with the total
1. Throttle grip free playThrottle g rip free play:
3.0–5.0 mm (0.12–0.20 in)
1
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Periodic maintenance an d a djustment
9-33
9 10. Close the seat.
EAU60701
Trou
bleshootin gAlthough Yamaha vehicles receive a
thorough inspection before shipment
from the factory, trouble may occur
during operation. Any problem in the
fuel, compression, or ignition systems,
for example, can cause poor starting
and loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your vehicle re-
quire any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the vehicle prop-
erly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWA15142
When checkin g the fuel system, d o
not smoke, an d make sure there are
no open flames or sparks in the ar-
ea, inclu din g pilot lig hts from water heaters or furnaces. Gasoline or
g
asoline vapors can i gnite or ex-
plod e, causin g severe injury or prop-
erty damag e.
EAU76551
Smart key system trou bleshootin g
Please check the following items when
the smart key system does not work.  Is the smart key turned on? (See
page 3-4.)
 Is the smart key battery dis-
charged? (See page 3-6.)
 Is the smart key battery installed
correctly? (See page 3-6.)
 Is the smart key being used in a lo-
cation with strong radio waves or
other electromagnetic noise? (See
page 3-1.)
 Are you using the smart key that is
registered to the vehicle?
 Is the vehicle battery discharged?
When the vehicle battery is dis-
charged, the smart key system will
not operate. Please have the vehi-
cle battery charged or replaced.
(See page 9-28.)
Tightenin g torque:
Grab bar bolt:
17 N·m (1.7 kgf·m, 13 lb·ft)
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Specifications
11-1
11
Dimensions:Overall length:1935 mm (76.2 in)
Overall width:
740 mm (29.1 in)
Overall height: 1160 mm (45.7 in)
Seat height: 765 mm (30.1 in)
Wheelbase:
1340 mm (52.8 in)
Ground clearance: 125 mm (4.92 in)
Minimum turning radius: 2.0 m (6.56 ft)Wei ght:Curb weight:
131 kg (289 lb)Engine:Combustion cycle:
4-stroke
Cooling system: Liquid cooled
Valve train: SOHC
Number of cylinders:
Single cylinder
Displacement: 155 cm3
Bore  stroke:
58.0  58.7 mm (2.28  2.31 in)
Starting system:
Electric starter
Engine oil:Recommended brand:
SAE viscosity grades:
10W-40
Recommended engine oil grade: API service SG type or higher, JASO
standard MA or MB
Engine oil quantity: Oil change:0.90 L (0.95 US qt, 0.79 Imp.qt)Final transmission oil:Type:
Motor oil SAE 10W-40 type SG or higher
Quantity: 0.10 L (0.11 US qt, 0.09 Imp.qt)Coolant quantity:Coolant reservoir (up to the maximum level
mark):0.13 L (0.14 US qt, 0.11 Imp.qt)
Radiator (including all routes):
0.46 L (0.49 US qt, 0.40 Imp.qt)Fuel:Recommended fuel:Unleaded gasoline (E10 acceptable)
Octane number (RON):
90
Fuel tank capacity: 7.1 L (1.9 US gal, 1.6 Imp.gal)
Fuel reserve amount: 1.7 L (0.45 US gal, 0.37 Imp.gal)
Fuel injection:Throttle body:ID mark:B2T1Front tire:Type:
Tubeless
Size: 110/70-13M/C 48P
Manufacturer/model: DUNLOP/SCOOT SMART LRear tire:Type: Tubeless
Size: 130/70-13M/C 63P
Manufacturer/model:
DUNLOP/SCOOT SMART LLoa din g:Maximum load:
167 kg (368 lb)
(Total weight of rider, passenger, cargo and
accessories)Front brake:Type:
Hydraulic single disc brakeRear brake:Type:
Hydraulic single disc brakeFront suspension:Type:
Telescopic fork
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Consumer information
12-2
12The model label is affixed to the inside
of the rear storage compartment. (See
page 6-19.) Record the information on
this label in the space provided. This
information will be needed when order-
ing spare parts from a Yamaha dealer.
EAU69910
Dia
gnostic connectorThe diagnostic connector is located as
shown.
EAU85300
Vehicle data recor din gThis model’s ECU stores certain vehi-
cle data to assist in the diagnosis of
malfunctions and for research, statisti-
cal analysis and development purpos-
es.
Although the sensors and recorded
data will vary by model, the main data
points are:
 Vehicle status and engine perfor-
mance data
 Fuel-injection and emission-relat-
ed data
This data will be uploaded only when a
special Yamaha diagnostic tool is at-
tached to the vehicle, such as when
maintenance checks or service proce-
dures are performed.
Vehicle data uploaded will be handled
appropriately according to the follow-
ing Privacy Policy.
Privacy Policy
1. FI diagnostic connector
1
https://www.yamaha-motor.eu/eu/
privacy/privacy-policy.aspx
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Consumer information
12-3
12
Yamaha will not disclose this data to a
third party except in the following cas-
es. In addition, Yamaha may provide
vehicle data to a contractor in order to
outsource services related to the han-
dling of vehicle data. Even in this case,
Yamaha will require the contractor to properly handle the vehicle data we
provided and Yamaha will appropriate-
ly manage the data.  With the consent of the vehicle
owner
 Where obligated by law
 For use by Yamaha in litigation
 When the data is not related to an
individual vehicle nor owner
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