2021 YAMAHA NMAX 155 Battery

Operation and important ri din g points
8-2
8
EAU86741
Startin g the en gineThe ignition circuit cut-off system will
enable starting only when the side-
stand is up.
To start the engine1. Turn the main switch on.
2. Confirm the indicator and warning light(s) come on for a few sec-
onds, and then go off. (See page
6-1.)TIPDo not start the engine if the en-
gine trouble warning light remains
on.
 The ABS warning light should
come on and stay on until the ve-
hicle reaches a speed of 10 km/h
(6 mi/h).NOTICE
ECA24110
If a warnin g or in dicator li ght does
not work as d escribed a bove, have a
Yamaha dealer check the vehicle.3. Close the throttle completely.
4. While applying the front or rear
brake, push the start switch. 5. Release the start switch when the
engine starts, or after 5 seconds.
Wait 10 seconds before pressing
the switch again to allow battery
voltage to restore.
NOTICE
ECA11043
For maximum en gine life, never ac-
celerate har d when the en gine is
col d!
EAU45093
Startin g off1. While pulling the rear brake lever
with your left hand and holding the
grab bar with your right hand,
push the scooter off the center-
stand.
2. Sit astride the seat, and then ad- just the rear view mirrors.
3. Switch the turn signals 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 signals off.1. Grab bar
1
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Periodic maintenance an d a djustment
9-3
9
EAU71342
General maintenance an d lu brication chartNO. ITEM CHECK OR MAINTENANCE JOB ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
1 *Dia
gnostic system
check • Perform dynamic inspection us-
ing Yamaha diagnostic tool.
• Check the error codes. 
2 *Air filter element • Replace. Every 18000 km (10500 mi)
3 Air filter case check
hose • Clean.

4 *V-
belt case air filter
element • Clean.
• Replace if necessary.

5 *Battery • Check voltage.
• Charge if necessary.

6 *Front brake • Check operation, fluid level, and
for fluid leakage.
• Replace brake pads if necessary. 
7 *Rear brake • Check operation, fluid level, and
for fluid leakage.
• Replace brake pads if necessary. 
8 *Brake hose • Check for cracks or damage.

• Replace. Every 4 years
9 *Brake flui d • Change. Every 2 years
10 *Wheels • Check runout and for damage.
• Replace if necessary.

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Periodic maintenance an d a djustment
9-28
9
EAU23292
Checkin g the wheel bearin gsThe 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.
EAU50292
BatteryThe battery is located under the seat.
(See page 6-17.)
This model is equipped with a VRLA
(Valve Regulated Lead Acid) battery.
There is no need to check the electro-
lyte or to add distilled water. However,
the battery lead connections need to
be checked and, if necessary, tight-
ened.
WARNING
EWA10761
 Electrolyte is poisonous an d
d an gerous since it contains sul-
furic aci d, which causes severe b
urns. Avoi d any contact with
skin, eyes or clothin g an d al-
ways shiel d your eyes when
workin g near b atteries. In case
of contact, ad minister the fol-
lowin g FIRST AID.
EXTERNAL: Flush with plenty of water.
INTERNAL: Drink lar ge quan-
tities of water or milk an d im-
me diately call a physician.
EYES: Flush with water for 15 minutes an d seek prompt
me dical attention.
 Batteries pro duce explosive hy-
d ro gen gas. Therefore, keep
sparks, flames, ci garettes, etc.,
away from the battery an d pro-
vi de sufficient ventilation when
char gin g it in an enclose d
space.
 KEEP THIS AND ALL BATTER-
IES OUT OF THE REACH OF
CHILDREN.
To char ge the b attery
Have a Yamaha dealer charge the bat-
tery as soon as possible if it seems to
have discharged. Keep in mind that the
1. Positive battery lead (red)
2. Battery
3. Negative battery lead (black)
3
2
1
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Periodic maintenance an d a djustment
9-29
9 battery tends to discharge more quick-
ly if the vehicle is equipped with op-
tional electrical accessories.
NOTICE
ECA16522
To char
ge a VRLA (Valve Re gulate d
Lea d Aci d) battery, a special (con-
stant-volta ge) battery char ger is re-
quired . Using a conventional b attery
char ger will damag e the b attery.To store the b attery
1. If the vehicle will not be used for more than one month, remove the
battery, fully charge it, and then
place it in a cool, dry place.
NOTICE: When removin g the
b attery, be sure to turn the main
switch off, then disconnect the
ne gative lead before discon-
nectin g the positive lea d.
[ECA16304]
2. If the battery will be stored for
more than two months, check it at
least once a month and fully
charge it if necessary.
3. Fully charge the battery before in- stallation. NOTICE: When install-
in g the b attery, be sure to turn
the main switch off, then con- nect the positive lead
before
connectin g the ne gative lea d.
[ECA16842]
4. After installation, make sure that
the battery leads are properly con-
nected to the battery terminals.NOTICE
ECA16531
Always keep the b attery charged .
Storin g a d ischar ged battery can
cause permanent battery damag e.
EAUN2581
Replacin g the fusesThe fuse boxes, which contain the fus-
es for the individual circuits, are locat-
ed under panel C. (See page 9-7.)1. Fuse box
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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Periodic maintenance an d a djustment
9-35
9 If the engine is left stopped by the
Stop and Start System for a long
period of time, the battery could
become discharged.
If the engine still does not restart after
you checked the preceding conditions,
have a Yamaha dealer check the vehi-
cle as soon as possible.
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Periodic maintenance an d a djustment
9-36
9
EAU86350
Trou bleshootin g chart
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the battery.
Supply fuel.
The engine does not start.
Check the battery.
Try starting the engine.4. Compression
There is compression.
There is no compression.
The engine does not start.
Have a Yamaha dealer check the vehicle.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(s). Have a Yamaha dealer check the vehicle.
The engine does not start.
Check the compression.
Operate the electric starter.2. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.
DryWet
Try starting the engine.
Check the battery lead connections,
and charge the battery if necessary.
The engine does not start.
Check the ignition.
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Periodic maintenance an d a djustment
9-38
9
EAU76561
Emer gency mo de When the smart key is lost or dam-
aged, or its battery has discharged, the
vehicle can still be turned on and the
engine started. You will need the smart
key system identification number.
To operate the vehicle in emer gency
mo de
1. Stop the vehicle in a safe place and turn the main switch to “OFF”.
2. Push the main switch knob for 5 seconds until the smart key sys-
tem indicator light flashes once,
then release it. Repeat two more
times. The smart key system indi-
cator light will come on for three
seconds to indicate the transition
to emergency mode. 3. After the smart key system indica-
tor light goes off, input the identifi-
cation number as follows.
4. Inputting the identification number is done by counting the number of
flashes of the smart key system in-
dicator light. For example, if the identification
number is 123456:
Push and hold the knob.

The smart key system indicator
light will start to flash.

Release the knob after the smart
key system indicator light flashes
once.

The first digit of the identification
number has been set as “1”.

Push and hold the knob again.

1. Smart key system indicator light “ ”
1. Identification number card
1
868588
1
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