2020 YAMAHA NMAX 125 engine

Periodic maintenance and adjustment
9-17
91. Check the hose on the rear side of
the air filter case for accumulated
dirt or water.
2. If dirt or water is visible, remove
the hose from the clamp, clean it,
and then install it.
TIPIf dirt or water was found in the check
hose, be sure to check the air filter ele-
ment for excessive dirt or damage and
replace it if necessary.Replacing the air filter element
1. Place the vehicle on the center-
stand.
2. Remove the air filter case cover by
removing the screws.3. Pull the air filter element out.
4. Insert a new air filter element into
the air filter case. NOTICE: Make
sure that the air filter element is
properly seated in the air filter
case. The engine should never
be operated without the air filter
element installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.
[ECA10482]
NOTICE
ECA21220
The air filter element must be
replaced at the intervals speci-
fied in the periodic maintenance
chart.The air filter element should be
replaced more frequently if you
often ride in the rain or dusty ar-
eas.
The air filter cannot be cleaned
by blowing it with compressed
air. It must be replaced.
5. Install the air filter case cover by
installing the screws.
Cleaning the V-belt case check hose
1. Check the hose on the rear side of
the V-belt case for accumulated
dirt or water.
2. If dirt or water is visible, remove
the hose from the clamp, clean it,
and then install it.
1. Air filter case cover
2. Screw
21
2
2
1. Air filter element
11
1. V-belt case check hose
1
UBALE0E0.book Page 17 Wednesday, September 30, 2020 1:37 PM

Periodic maintenance and adjustment
9-19
9
EAU21386
Checking 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 adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
The tire air pressure must be
adjusted in accordance with the
riding speed and with the total
1. Throttle grip free playThrottle grip free play:
3.0–5.0 mm (0.12–0.20 in)
1
UBALE0E0.book Page 19 Wednesday, September 30, 2020 1:37 PM

Periodic maintenance and adjustment
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 and Start System trouble-
shooting
If a problem occurs, check the follow-
ing before taking the vehicle to a
Yamaha dealer.
The Stop and Start System indicator
light 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 and Start System indicator
light comes on, but 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 engine was stopped by the
Stop and Start System, the engine
does not restart even if the throttle
grip is turned.
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
UBALE0E0.book Page 34 Wednesday, September 30, 2020 1:37 PM

Periodic maintenance and adjustment
9-35
9If 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.
UBALE0E0.book Page 35 Wednesday, September 30, 2020 1:37 PM

Periodic maintenance and adjustment
9-36
9
EAU86350
Troubleshooting 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.
UBALE0E0.book Page 36 Wednesday, September 30, 2020 1:37 PM

Periodic maintenance and adjustment
9-37
9
EAU86420
Engine overheating
WARNING
EWAT1041
Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.
Place a thick rag, like a towel, over the radiator cap, and then slowly rotate the cap counterclockwise to the
detent to allow any residual pressure to escape. When the hissing sound has stopped, press down on the cap
while turning it counterclockwise, and 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.
UBALE0E0.book Page 37 Wednesday, September 30, 2020 1:37 PM

Periodic maintenance and adjustment
9-38
9
EAU76561
Emergency mode 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 emergency
mode
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
UBALE0E0.book Page 38 Wednesday, September 30, 2020 1:37 PM

Motorcycle care and storage
10-3
10 will become slippery, which
could cause loss of control.
Thoroughly clean the surfaces
of these parts before operating
the vehicle.
[EWA20650]
5. Treat rubber, vinyl, and unpainted
plastic parts with a suitable care
product.
6. Touch up minor paint damage
caused by stones, etc.
7. Wax all painted surfaces using a
non-abrasive wax or use a detail
spray for motorcycles.
8. When finished cleaning, start the
engine and let it idle for several
minutes to help dry any remaining
moisture.
9. If the headlight lens has fogged
up, start the engine and turn on
the headlight to help remove the
moisture.
10. Let the vehicle dry completely be-
fore storing or covering it.NOTICE
ECA26320
Do not apply wax to rubber or
unpainted plastic parts.Do not use abrasive polishing
compounds as they will wear
away the paint.
Apply sprays and wax sparingly.
Wipe off excess afterwards.
WARNING
EWA20660
Contaminants left on the brakes or
tires can cause loss of control.
Make sure there is no lubricant
or wax on the brakes or tires.
If necessary, wash the tires with
warm water and a mild deter-
gent.
If necessary, clean the brake
discs and pads with brake
cleaner or acetone.
Before riding at higher speeds,
test the vehicle’s braking per-
formance and cornering behav-
ior.
EAU83472
StorageAlways store the vehicle in a cool, dry
place. If necessary, protect it against
dust with a porous cover. Be sure the
engine and the exhaust system are
cool before covering the vehicle. If the
vehicle often sits for weeks at a time
between uses, the use of a quality fuel
stabilizer is recommended after each
fill-up.NOTICE
ECA21170
Storing the vehicle in a poorly
ventilated room or covering it
with a tarp, while it is still wet,
will allow water and humidity to
seep in and cause rust.
To prevent corrosion, avoid
damp cellars, stables (because
of the presence of ammonia)
and areas where strong chemi-
cals are stored.Long term storage
Before storing the vehicle long term (60
days or more):
UBALE0E0.book Page 3 Wednesday, September 30, 2020 1:37 PM