2021 YAMAHA NMAX 155 light

Periodic maintenance an d a djustment
9-9
9 2. Install the windshield by installing
the screws.
EAU67161
Checkin g the spark plu gThe 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 main-
tenance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
To remove the spark plu g
1. Place the vehicle on the center- stand.
2. Remove panels A and B. (See page 9-7.)
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 plu g
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 vehi-
cle is ridden normally).
TIPIf 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.
1. Spark plug cap
1
1. Spark plug wrench
1
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Periodic maintenance an d a djustment
9-11
9
EAU36113
CanisterThis model is equipped with a canister
to prevent the discharging of fuel vapor
into the atmosphere. Before operating
this vehicle, make sure to check the
following:
 Check each hose connection.
 Check each hose and canister for
cracks or damage. Replace if
damaged.
 Make sure that the canister
breather is not blocked, and if
necessary, clean it.
EAU66995
Engine oil an d oil strainerThe engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil strainer
cleaned at the intervals specified in the
periodic maintenance and lubrication
chart.
To check the en gine oil level
1. Place the vehicle on the center- stand. A slight tilt to the side can
result in a false reading.
2. Start the engine, warm it up for several minutes, and then turn it
off.
3. Wait a few minutes until the oil set- tles, remove the engine oil filler
cap, wipe the engine oil dipstick
clean, insert it back into the oil fill-
er hole (without screwing it in), and
then remove it again to check the
oil level. WARNING! The muffler
an d muffler protector become
very hot d uring use. To avoi d
possi ble burns, let the muffler
an d protector cool before re-
movin g the oil filler cap.
[EWA17810]
TIPThe engine oil should be between the
tip of the dipstick and the maximum
level mark.4. If the engine oil is not between the
tip of the dipstick and the maxi-
mum level mark, add sufficient oil
of the recommended type to raise
it to the correct level.
5. Insert the dipstick into the oil filler hole, and then tighten the oil filler
cap.
1. Canister
2. Canister breather
2
1
1. Oil filler hole
2. O-ring
3. Engine oil dipstick
4. Maximum level mark
5. Tip of the engine oil dipstick
3245
1
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Periodic maintenance an d a djustment
9-15
9
EAU20071
CoolantThe coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUN2930
To check the coolant level
1. Place the vehicle on the center- stand.TIPThe coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
 Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to the
side can result in a false reading.2. Check the coolant level in the
coolant reservoir.TIPThe coolant should be between the
minimum and maximum level marks.
3. If the coolant is at or below theminimum level mark, remove the
right floorboard mat by pulling it
up.
4. Remove the coolant reservoir cov- er. 5. Remove the coolant reservoir cap,
add coolant to the maximum level
mark, and then install the reservoir
cap. WARNING! Remove only
the coolant reservoir cap. Never
attempt to remove the ra diator
cap when the en gine is hot.
[EWA15162]
NOTICE: If coolant is not
availa ble, use d istilled water or
soft tap water instea d. Do not
use har d water or salt water
since it is harmful to the en gine.
If water has been used instead
of coolant, replace it with cool-
ant as soon as possi ble, other-
wise the coolin g system will not
b e protecte d a gainst frost an d
corrosion. If water has been
1. Maximum level mark
2. Minimum level mark
1. Floorboard mat
1
2
1
1. Coolant reservoir cover
1
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Periodic maintenance an d a djustment
9-30
9
If a fuse is blown, replace it as follows. 1. Turn off the electrical circuit in question, and then turn off the
main switch.
2. Remove the panel C. (See page 9-7.) 3. Remove the blown fuse, and then
install a new fuse of the specified
amperage. WARNING! Do not
use a fuse of a hi gher ampera ge
ratin g than recommen ded to
avoi d causin g extensive dam-
a g e to the electrical system an d
possi bly a fire.
[EWA15132]
4. Turn the main switch on, and then
turn on the electrical circuit in
question to check if the device op-
erates.TIPIf the fuse immediately blows again,
have a Yamaha dealer check the elec-
trical system.5. Install the panel C. (See page 9-7.)
1. Signaling system fuse
2. Terminal fuse 1
3. Smart key system fuse
4. ABS motor fuse
5. ABS solenoid fuse
6. Spare fuse
7. Fuel injection system fuse
8. Backup fuse
9. Main fuse
10.Ignition fuse
11.Headlight fuse
12.ABS control unit fuse1
6
2
3
4
5
7
8
9
11
12
610
Specified
fuses:
Main fuse: 30.0 A
Terminal fuse 1:
5.0 A
Headlight fuse: 7.5 A
Signaling system fuse: 7.5 A
Ignition fuse:
7.5 A
Smart key system fuse: 2.0 A
ABS motor fuse: 30.0 A
Fuel injection system fuse:
7.5 A
ABS solenoid fuse: 15.0 A
ABS control unit fuse: 2.0 A
Backup fuse:
7.5 A
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Periodic maintenance an d a djustment
9-31
9
EAUN2261
Vehicle li ghtsThis model is equipped with LED lights
for headlights, auxiliary lights and
brake/tail light. If a light does not come
on, check the fuse and then have a
Yamaha dealer check the vehicle.NOTICE
ECA16581
Do not affix any type of tinted film or
stickers to the head light lens.
EAU43054
Replacin g a front turn si gnal
li g ht bul b1. Place the vehicle on the center-
stand.
2. Remove the turn signal light bulb socket (together with the bulb) by
turning it counterclockwise.
3. Remove the burnt-out bulb by pulling it out. 4. Insert a new bulb into the socket.
5. Install the socket (together with
the bulb) by turning it clockwise.
1. Headlight (high beam)
2. Headlight (low beam)
3. Auxiliary light
2
3
1
1. Turn signal light bulb socket
1
1. Turn signal light bulb
1
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Periodic maintenance an d a djustment
9-32
9
EAU67320
Replacin g a rear turn si gnal
lig ht bul b1. Open the seat. (See page 6-17.)
2. Remove the grab bar by removing
the bolts.
3. Remove the taillight cover by re- moving the screws. 4. Remove the turn signal light bulb
socket (together with the bulb) by
turning it counterclockwise.
5. Remove the burnt-out bulb by pulling it out. 6. Insert a new bulb into the socket.
7. Install the socket (together with
the bulb) by turning it clockwise.
8. Install the taillight cover by install- ing the screws.
9. Install the grab bar by installing the bolts, and then tightening them to
the specified torque.1. Grab bar
2. Bolt1
2
1. Taillight cover
2. Screw
1. Turn signal light bulb socket1 2
1
1. Turn signal light bulb
1
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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
9-38
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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