engine coolant YAMAHA NMAX 125 2021 Owners Manual
Page 8 of 114
Table of contentsSafety information............................ 1-1
Further safe-riding points ............... 1-5
Description....................................... 2-1
Left view ......................................... 2-1
Right view ....................................... 2-2
Controls and instruments ............... 2-3
Smart key system ........................... 3-1
Smart key system ........................... 3-1
Operating range of the smart key 
system......................................... 3-2
Handling of the smart key and 
mechanical keys ......................... 3-3
Smart key ....................................... 3-4
Replacing the smart key battery..... 3-6
Main switch .................................... 3-7
Stop and Start System..................... 4-1
Stop and Start System ................... 4-1
Stop and Start System operation ... 4-1
Special features .............................. 5-1
CCU (Communication Control 
Unit) ............................................. 5-1
Instrument and control functions... 6-1
Indicator lights and warning 
lights............................................ 6-1
Multi-function meter unit ................ 6-3
Handlebar switches ........................ 6-9Front brake lever ........................... 6-11
Rear brake lever ............................ 6-11
ABS ............................................... 6-11
Traction control system ................ 6-12
Fuel tank cap ................................ 6-14
Fuel ............................................... 6-15
Fuel tank overflow hose ................ 6-16
Catalytic converter ........................ 6-16
Seat ............................................... 6-17
Helmet holders .............................. 6-17
Storage compartments ................. 6-18
Adjusting the shock absorber 
assemblies ................................. 6-19
Power outlet  ................................. 6-20
Sidestand ...................................... 6-21
Ignition circuit cut-off system ....... 6-22
For your safety – pre-operation 
checks............................................... 7-1
Operation and important riding 
points................................................. 8-1
Engine break-in ............................... 8-1
Starting the engine .......................... 8-2
Starting off ...................................... 8-2
Acceleration and deceleration ........ 8-3
Braking ............................................ 8-3
Tips for reducing fuel 
consumption ................................ 8-3
Parking ........................................... 8-4Periodic maintenance and 
adjustment........................................ 9-1
Tool kit ............................................ 9-1
Periodic maintenance chart for 
the emission control system ....... 9-2
General maintenance and 
lubrication chart .......................... 9-3
Removing and installing panels ...... 9-7
Checking the spark plug................. 9-9
Canister ........................................ 9-11
Engine oil and oil strainer ............. 9-11
Why Yamalube.............................. 9-13
Final transmission oil .................... 9-13
Coolant ......................................... 9-15
Air filter and V-belt case air filter 
elements .................................... 9-16
Checking the throttle grip 
free play..................................... 9-19
Valve clearance............................. 9-19
Tires .............................................. 9-19
Cast wheels .................................. 9-21
Checking the front and rear 
brake lever free play .................. 9-21
Checking the front and rear 
brake pads ................................ 9-22
Checking the brake fluid level ...... 9-23
Changing the brake fluid .............. 9-24
Checking the V-belt ...................... 9-24
Checking and lubricating the 
cables ........................................ 9-25UBALE0E0.book  Page 1  Wednesday, September 30, 2020  1:37 PM 
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Description
2-2
2
EAU10421
Right view
1
10 9 8 7 623 4 5
1. Tail/brake light
2. Battery (page 9-28)
3. Storage compartment B (page 6-18)
4. Fuse box (page 9-29)
5. Headlight (page 9-31)
6. Coolant reservoir (page 9-15)
7. Spark plug (page 9-9)
8. Engine oil drain bolt A (page 9-11)9. Engine oil drain bolt B (page 9-11)
10.Engine oil filler cap (page 9-11)
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Instrument and control functions
6-5
6 4. Use the “MENU” switch to set the
minutes.
5. Push the “MENU” switch until the
minute digits stop flashing. The
setting is confirmed.
TIPWhen CCU and smartphone is con-
nected after vehicle power on, the
clock is automatically adjusted.
EAU86860
Coolant temperature meter
This meter shows the temperature of
the coolant, and thereby the condition
of the engine. The segments come on
from “C” (cold) to “H” (hot) as the en-
gine temperature increases. If the hotsegment flashes, stop the engine as
soon as possible, and let the engine
cool. (See page 9-37.)
TIPIf a problem is detected in the electrical
circuit, all segments will flash repeat-
edly. Have a Yamaha dealer check the
vehicle.
EAU86870
VVA indicator
This model is equipped with variable
valve actuation (VVA) for good fuel
economy and acceleration in both the
low-speed and high-speed ranges.
The VVA indicator comes on when the
variable valve actuation system has
switched to the high-speed range.To turn the VVA indicator on or off
1. Turn the vehicle off.
2. While pushing the “MENU”
switch, turn the vehicle on.
3. Continue pushing the “MENU”
switch. The display unit setting
screen will come on (after 5 sec-
onds), and after that (an additional
10 seconds) all segments other
than the VVA indicator will start
flashing. Now release the “MENU”
switch.
4. Push the “MENU” switch once to
change the on or off setting.
5. Push the “MENU” switch for 1
second to confirm the setting.TIPTurning the VVA indicator off does not
turn off the variable valve actuation
system.
1. Coolant temperature meter
1
1. VVA (variable valve actuation) indicator
1
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For your safety – pre-operation checks
7-1
7
EAU1559B
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWA11152
Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equipment damage.
Do not operate the vehicle if you find any problem. If a problem cannot be corrected by the procedures provided in
this manual, have the vehicle inspected by a Yamaha dealer.Before using this vehicle, check the following points:
ITEM CHECKS PAGE
Fuel• Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage.
• Check fuel tank overflow hose for obstructions, cracks or damage, and check 
hose connection.6-15, 6-16
Engine oil• Check oil level in engine.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.9-11
Final transmission oil• Check vehicle for oil leakage. 9-13
Coolant• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified level.
• Check cooling system for leakage.9-15
Front brake• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage.9-21, 9-22, 9-23
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Periodic maintenance and adjustment
9-5
9
20 Engine oil• Change (warm engine before 
draining).
• Check oil level and vehicle for oil 
leakage.At the initial interval and when the oil change indicator flashes or 
comes on.√
21*Engine oil strainer• Clean.√
22*Final transmission 
oil• Check vehicle for oil leakage.√√√√√
• Change.√√√
23*Cooling system• Check coolant level and vehicle 
for coolant leakage.√√√√√
• Change. Every 3 years
24*V-belt• Replace. When the V-belt replacement indicator flashes or comes on
25*Front and rear 
brake switches• Check operation.√√√√√√
26*Moving parts and 
cables• Lubricate.√√√√√
27*Throttle grip hous-
ing and cable• Check operation and free play.
• Adjust the throttle cable free play 
if necessary.
• Lubricate the throttle grip housing 
and cable.√√√√√
28*Lights, signals and 
switches• Check operation.
• Adjust headlight beam.√√√√√√ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING
ANNUAL 
CHECK 1000 km 
(600 mi)6000 km 
(3500 mi)12000 km 
(7000 mi)18000 km 
(10500 mi)24000 km 
(14000 mi)
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Periodic maintenance and adjustment
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.TIPThe 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 the
minimum 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 radiator
cap when the engine is hot.
[EWA15162]
 NOTICE: If coolant is not
available, use distilled water or
soft tap water instead. Do not
use hard water or salt water
since it is harmful to the engine.
If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the cooling system will not
be protected against frost and
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 and adjustment
9-16
9 added to the coolant, have a
Yamaha dealer check the anti-
freeze content of the coolant as
soon as possible, otherwise the
effectiveness of the coolant will
be reduced.
 [ECA10473]
6. Install the coolant reservoir cover.
7. Place the right floorboard mat in
the original position and push it
downward to secure it.
EAU33032
Changing the coolant
The coolant must be changed at the in-
tervals specified in the periodic main-
tenance and lubrication chart. Have a
Yamaha dealer change the coolant.
WARNING! Never attempt to remove
the radiator cap when the engine is
hot.
 [EWA10382]EAU67174
Air filter and V-belt case air fil-
ter elementsThe air filter element should be re-
placed and the V-belt case air filter el-
ement should be cleaned at the
intervals specified in the periodic main-
tenance and lubrication chart. Service
the air filter elements more frequently if
you are riding in unusually wet or dusty
areas. The air filter check hose and V-
belt case air filter check hose must be
frequently checked and cleaned if nec-
essary.
Cleaning the air filter check hose
1. Coolant reservoir capCoolant reservoir capacity (up to 
the maximum level mark):
0.13 L (0.14 US qt, 0.11 Imp.qt)
1
1. Air filter check hose
1
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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.
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Specifications
11-1
11
Dimensions:Overall length:
1935 mm (76.2 in)
Overall width:
740 mm (29.1 in)
Overall height:
1160 mm (45.7 in)
Seat height:
765 mm (30.1 in)
Wheelbase:
1340 mm (52.8 in)
Ground clearance:
125 mm (4.92 in)
Minimum turning radius:
2.0 m (6.56 ft)Weight:Curb weight:
131 kg (289 lb)Engine:Combustion cycle:
4-stroke
Cooling system:
Liquid cooled
Valve train:
SOHC
Number of cylinders:
Single cylinder
Displacement:
125 cm3
Bore × stroke:
52.0 × 58.7 mm (2.05 × 2.31 in)
Starting system:
Electric starter
Engine oil:Recommended brand:
SAE viscosity grades:
10W-40
Recommended engine oil grade:
API service SG type or higher, JASO 
standard MA or MB
Engine oil quantity:
Oil change:
0.90 L (0.95 US qt, 0.79 Imp.qt)Final transmission oil:Type:
Motor oil SAE 10W-40 type SG or higher
Quantity:
0.10 L (0.11 US qt, 0.09 Imp.qt)Coolant quantity:Coolant reservoir (up to the maximum level 
mark):
0.13 L (0.14 US qt, 0.11 Imp.qt)
Radiator (including all routes):
0.46 L (0.49 US qt, 0.40 Imp.qt)Fuel:Recommended fuel:
Unleaded gasoline only
Octane number (RON):
90
Fuel tank capacity:
7.1 L (1.9 US gal, 1.6 Imp.gal)
Fuel reserve amount:
1.7 L (0.45 US gal, 0.37 Imp.gal)
Fuel injection:Throttle body:
ID mark:
B2T1Front tire:Type:
Tubeless
Size:
110/70-13M/C 48P
Manufacturer/model:
DUNLOP/SCOOT SMART LRear tire:Type:
Tubeless
Size:
130/70-13M/C 63P
Manufacturer/model:
DUNLOP/SCOOT SMART LLoading:Maximum load:
167 kg (368 lb)
(Total weight of rider, passenger, cargo and 
accessories)Front brake:Type:
Hydraulic single disc brakeRear brake:Type:
Hydraulic single disc brakeFront suspension:Type:
Telescopic fork
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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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