2020 YAMAHA NMAX 125 check engine

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
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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
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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.
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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

Motorcycle care and storage
10-4
101. Make all necessary repairs and
perform any outstanding mainte-
nance.
2. Follow all instructions in the Care
section of this chapter.
3. Fill up the fuel tank, adding fuel
stabilizer according to product in-
structions. Run the engine for 5
minutes to distribute treated fuel
through the fuel system.
4. For vehicles equipped with a fuel
cock: Turn the fuel cock lever to
the off position.
5. For vehicles with a carburetor: To
prevent fuel deposits from build-
ing up, drain the fuel in the carbu-
retor float chamber into a clean
container. Retighten the drain bolt
and pour the fuel back into the fuel
tank.
6. Use a quality engine fogging oil
according to product instructions
to protect internal engine compo-
nents from corrosion. If engine
fogging oil is not available, per-
form the following steps for each
cylinder:
a. Remove the spark plug cap
and spark plug.b. Pour a teaspoonful of engine
oil into the spark plug bore.
c. Install the spark plug cap onto
the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several
times with the starter. (This will
coat the cylinder wall with oil.)
WARNING! To prevent dam-
age or injury from sparking,
make sure to ground the
spark plug electrodes while
turning the engine over.
[EWA10952]
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
7. Lubricate all control cables, piv-
ots, levers and pedals, as well as
the sidestand and centerstand (if
equipped).
8. Check and correct the tire air
pressure, and then lift the vehicle
so that all wheels are off the
ground. Otherwise, turn thewheels a little once a month in or-
der to prevent the tires from be-
coming degraded in one spot.
9. Cover the muffler outlet with a
plastic bag to prevent moisture
from entering it.
10. Remove the battery and fully
charge it, or attach a maintenance
charger to keep the battery opti-
mally charged. NOTICE: Confirm
that the battery and its charger
are compatible. Do not charge a
VRLA battery with a convention-
al charger.
[ECA26330]
TIPIf the battery will be removed,
charge it once a month and store
it in a temperate location between
0-30 °C (32-90 °F).
See page 9-28 for more informa-
tion on charging and storing the
battery.
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Consumer information
12-2
12The model label is affixed to the inside
of the rear storage compartment. (See
page 6-18.) 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
Diagnostic connectorThe diagnostic connector is located as
shown.
EAU85300
Vehicle data recordingThis 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
UBALE0E0.book Page 2 Wednesday, September 30, 2020 1:37 PM

13-1
13
IndexAABS ....................................................... 6-11
ABS warning light ................................... 6-2
Acceleration and deceleration ................ 8-3
Activating the Stop and Start System .... 4-1
Air filter and V-belt case air filter
elements ............................................. 9-16
App Connect icon ................................... 6-4BBattery .................................................. 9-28
Brake fluid, changing ............................ 9-24
Brake fluid level, checking .................... 9-23
Brake lever, front .................................. 6-11
Brake lever, rear.................................... 6-11
Brake levers, lubricating ....................... 9-25
Braking.................................................... 8-3CCables, checking and lubricating ......... 9-25
Canister................................................. 9-11
Care ...................................................... 10-1
Catalytic converter ................................ 6-16
CCU (Communication Control Unit) ....... 5-1
Centerstand and sidestand,
checking and lubricating .................... 9-26
Clock....................................................... 6-4
Coolant ................................................. 9-15
Coolant temperature meter .................... 6-5DData recording, vehicle ......................... 12-2
Diagnostic connector............................ 12-2
Dimmer switch ...................................... 6-10
Display units, switching .......................... 6-4EEmergency mode.................................. 9-38Engine break-in ...................................... 8-1
Engine oil and oil strainer ..................... 9-11
Engine overheating ............................... 9-37
Engine serial number ............................ 12-1
FFinal transmission oil ............................ 9-13
Front and rear brake lever free play,
checking............................................. 9-21
Front and rear brake pads, checking ... 9-22
Front fork, checking ............................. 9-27
Fuel ....................................................... 6-15
Fuel consumption, tips for reducing ...... 8-3
Fuel meter .............................................. 6-4
Fuel tank cap ........................................ 6-14
Fuel tank overflow hose ....................... 6-16
Fuses, replacing ................................... 9-29HHandlebar switches ................................ 6-9
Hazard switch....................................... 6-10
Helmet holders ..................................... 6-17
High beam indicator light ....................... 6-1
Horn switch .......................................... 6-10IIdentification numbers .......................... 12-1
Ignition circuit cut-off system ............... 6-22
Incoming call indicator light ................... 6-3
Incoming notification indicator light ....... 6-3
Indicator lights and warning lights ......... 6-1KKey, handling of smart and
mechanical keys................................... 3-3MMain switch ............................................ 3-7
Maintenance and lubrication, periodic ... 9-3Maintenance, emission control
system ..................................................9-2
Malfunction indicator light (MIL)..............6-1
Matte color, caution ..............................10-1
Menu switch..........................................6-10
Model label ...........................................12-1
Multi-function display .............................6-6
Multi-function meter unit .........................6-3
OOperating range of the smart key
system ..................................................3-2PPanels, removing and installing ..............9-7
Parking ....................................................8-4
Part locations ..........................................2-1
Power outlet ..........................................6-20
Precautions when using the
Stop and Start System .........................4-3SSafe-riding points....................................1-5
Safety information ...................................1-1
Seat .......................................................6-17
Shock absorber assemblies,
adjusting .............................................6-19
Sidestand ..............................................6-21
Smart key ................................................3-4
Smart key battery, replacing ...................3-6
Smart key system ...................................3-1
Smart key system indicator light.............6-2
Smart key system, troubleshooting ......9-33
Spark plug, checking ..............................9-9
Special features ......................................5-1
Specifications .......................................11-1
Speedometer ..........................................6-4
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