2021 YAMAHA NMAX 155 Owners Manual

Periodic maintenance an d a djustment
9-34
9
If the smart key system does not work
after checking the above items, have a
Yamaha dealer check the smart key system.
TIPSee Emergency mode on page 9-38
for information on starting the engine
without the smart key.
EAU76843
Stop an d Start System trou ble-
shootin g
If a problem occurs, check the follow-
ing before taking the vehicle to a
Yamaha dealer.
The Stop an d Start System in dicator
lig ht does not come on.
1. Is the main switch turned on?
2. Is the Stop and Start System switch set to “ ”?
3. Was the engine warmed up suffi- ciently after starting?
4. After the engine was warmed up, was the engine left idling for a cer-
tain period of time?
5. Did the vehicle travel at a speed of 10 km/h or higher? Even if the preceding conditions are
met, the Stop and Start System may
not activate in order to preserve bat-
tery power. In this case, continue to
drive the vehicle.
In addition, the Stop and Start System
indicator light does not come on if the
engine trouble warning light is on.
If the Stop and Start System indicator
light still does not come on after you
checked the preceding conditions,
have a Yamaha dealer check the vehi-
cle as soon as possible.
The Stop an
d Start System in dicator
li g ht comes on, b ut the engine does
not stop automatically. 1. Was the vehicle stopped com- pletely?
The engine may not stop automat-
ically until the vehicle is stopped
for a certain period of time. Try
bringing the vehicle to a complete
stop.
2. Is the throttle grip turned? The engine does not stop auto-
matically if the throttle grip is not in
the fully closed position. Turn the throttle grip to the fully
closed position.
If the engine still does not stop auto-
matically after you checked the pre-
ceding conditions, have a Yamaha
dealer check the vehicle as soon as
possible.
After the eng ine was stopped b y the
Stop an d Start System, the en gine
d oes not restart even if the throttle
g rip is turne d.
1. Is the Stop and Start System switch set to “ ”?
If the Stop and Start System
switch is set to “ ” while the Stop
and Start System is activated, the
Stop and Start System will be
turned off.
2. Was the sidestand operated? When the sidestand is lowered,
the Stop and Start System is de-
activated.
3. Was the engine left stopped by the Stop and Start System for a
long period of time?
A
AA
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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.
UBBDE0E0.book Page 36 Wednesday, June 2, 2021 2:57 PM

Periodic maintenance an d a djustment
9-37
9
EAU86420
En gine overheatin g
WARNING
EWAT1041
Do not remove the ra diator cap when the en gine an d ra diator are hot. Scal din g hot flui d an d steam may be
b lown out un der pressure, which coul d cause serious injury. Be sure to wait until the en gine has cooled .
 Place a thick ra g, like a towel, over the ra diator cap, an d then slowly rotate the cap counterclockwise to the
d etent to allow any resi dual pressure to escape. When the hissin g soun d has stoppe d, press d own on the cap
while turnin g it counterclockwise, an d then remove the cap.TIPIf coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended cool-
ant as soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See TIP.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.
UBBDE0E0.book Page 37 Wednesday, June 2, 2021 2:57 PM

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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Periodic maintenance an d a djustment
9-39
9 Release the knob after the smart
key system indicator light flashes
twice.

The second digit has been set as
“2”.

Repeat the above procedure until
all digits of the identification num-
ber have been set. The smart key
system indicator light will flash for
10 seconds if the correct identifi-
cation number was entered.
TIPWhen one of the following situations
applies, emergency mode will be ter-
minated and the smart key system in-
dicator light will flash quickly for 3
seconds. In this case, start over again
from step 2.
 When there are no knob opera-
tions for 10 seconds during the
identification number input pro-
cess.
 When the smart key system indi-
cator light is allowed to flash nine
or more times. 
The identification number is not
entered correctly.
5. While the smart key system indi-
cator light is on, push the knob
once more to complete emergen-
cy mode access. The smart key
indicator light will go off and then
come back on for approximately 4
seconds.
6. While the smart key system indi- cator light is on, turn the main
switch to “ON”. The vehicle can
now be operated normally.
UBBDE0E0.book Page 39 Wednesday, June 2, 2021 2:57 PM

Motorcycle care and stora ge
10-1
10
EAU37834
Matte color cautionNOTICE
ECA15193
Some mo dels are equipped with
matte colored finished parts. Be
sure to consult a Yamaha dealer for
a d vice on what prod ucts to use be-
fore cleanin g the vehicle. Usin g a
b rush, harsh chemical pro ducts or
cleanin g compoun ds when cleanin g
these parts will scratch or damag e
their surface. Wax also shoul d not
b e applie d to any matte colored fin-
ishe d parts.
EAU83443
CareFrequent, thorough cleaning of the ve-
hicle will not only enhance its appear-
ance but also will improve its general
performance and extend the useful life
of many components. Washing, clean-
ing, and polishing will also give you a
chance to inspect the condition of the
vehicle more frequently. Be sure to
wash the vehicle after riding in the rain
or near the sea, because salt is corro-
sive to metals.TIP The roads of heavy snowfall areas
may be sprayed with salt as a de-
icing method. This salt can stay on
the roads well into spring, so be
sure to wash the underside and
chassis parts after riding in such
areas.
 Genuine Yamaha care and main-
tenance products are sold under
the YAMALUBE brand in many
markets worldwide.
 See your Yamaha dealer for addi-
tional cleaning tips.
NOTICE
ECA26280
Improper cleanin g can cause cos-
metic an d mechanical damag e. Do
not use:  high-pressure washers or
steam-jet cleaners. Excessive
water pressure may cause wa-
ter seepag e and d eterioration of
wheel bearin gs, brakes, trans-
mission seals an d electrical de-
vices. Avoi d hi gh-pressure
d eter gent applications such as
those availa ble in coin-operate d
car washers.
 harsh chemicals, inclu din g
stron g aci dic wheel cleaners,
especially on spoke or ma gne-
sium wheels.
 harsh chemicals, a brasive
cleanin g compoun ds, or wax on
matte-finishe d parts. Brushes
can scratch an d damag e the
matte-finish, use soft spon ge or
towel only.
 towels, spon ges, or brushes
contaminate d with a brasive
cleanin g prod ucts or stron g
UBBDE0E0.book Page 1 Wednesday, June 2, 2021 2:57 PM

Motorcycle care and stora ge
10-2
10 chemicals such as, solvents,
g
asoline, rust removers, b rake
flui d, or antifreeze, etc.
Before washin g
1. Park the vehicle out of direct sun- light and allow it to cool. This will
help avoid water spots.
2. Make sure all caps, covers, elec- trical couplers and connectors are
tightly installed.
3. Cover the muffler end with a plas- tic bag and a strong rubber band.
4. Pre-soak stubborn stains like in- sects or bird droppings with a wet
towel for a few minutes.
5. Remove road grime and oil stains with a quality degreasing agent
and a plastic-bristle brush or
sponge. NOTICE: Do not use
d eg reasin g a gent on areas re-
quirin g lu brication such as
seals, gaskets, an d wheel axles.
Follow prod uct instructions.
[ECA26290]
Washing
1. Rinse off any degreaser and spray down the vehicle with a garden
hose. Use only enough pressure
to do the job. Avoid spraying wa-
ter directly into the muffler, instru-
ment panel, air inlet, or other inner
areas such as underseat storage
compartments.
2. Wash the vehicle with a quality au- tomotive-type detergent mixed
with cool water and a soft, clean
towel or sponge. Use an old tooth-
brush or plastic-bristle brush for
hard-to-reach places. NOTICE:
Use col d water if the vehicle has
b een exposed to salt. Warm wa-
ter will increase salt’s corrosive
properties.
[ECA26301]
3. For windshield-equipped vehicles: Clean the windshield with a soft
towel or sponge dampened with
water and a pH neutral detergent.
If necessary, use a high-quality
windshield cleaner or polish for
motorcycles. NOTICE: Never use
any stron g chemicals to clean
the win dshiel d. A dditionally,
some cleanin g compoun ds for plastic may scratch the win
d-
shiel d, so b e sure to test all
cleanin g prod ucts before gen-
eral application.
[ECA26310]
4. Rinse off thoroughly with clean water. Be sure to remove all deter-
gent residues, as they can be
harmful to plastic parts.
After washin g
1. Dry the vehicle with a chamois or absorbent towel, preferably mi-
crofiber terrycloth.
2. For drive chain-equipped models: Dry and then lubricate the drive
chain to prevent rust.
3. Use a chrome polish to shine chrome, aluminum, and stainless
steel parts. Often the thermally in-
duced discoloring of stainless
steel exhaust systems can be re-
moved through polishing.
4. Apply a corrosion protection spray on all metal parts including
chrome or nickel-plated surfaces.
WARNING! Do not apply sili-
cone or oil spray to seats, han d
g rips, ru bber foot peg s or tire
trea ds. Otherwise these parts
UBBDE0E0.book Page 2 Wednesday, June 2, 2021 2:57 PM