2018 YAMAHA NMAX 125 fuel

Periodic maintenance an d a djustment
6-39
6
10. Close the seat.
EAU25883
Trou
bleshootin g
Although Yamaha scooters receive a
thorough inspection before shipment
from the factory, trouble may occur
during operation. Any problem in the
fuel, compression, or ignition systems,
for example, can cause poor starting
and loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your scooter re-
quire any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the scooter prop-
erly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWA15142
When checkin g the fuel system, do
not smoke, an d make sure there are
no open flames or sparks in the ar-
ea, inclu din g pilot li ghts from water
heaters or furnaces. Gasoline or
g asoline vapors can i gnite or ex-
plo de, causin g severe injury or prop-
erty damag e.
Tightening torque:
Grab bar bolt: 17 N·m (1.7 kgf·m, 12 lb·ft)
UBV3E0E0.book Page 39 Monday, September 26, 2016 3:42 PM

Periodic maintenance an d a djustment
6-40
6
EAU68020
Trou bleshootin g charts
Startin g pro blems or poor en gine performance
1. FuelThere is enough fuel.
There is no fuel.
Check the battery.
Supply fuel.
The engine turns over
quickly.
The engine turns over
slowly.
Operate the electric
starter.
The engine does not
start.
Check the battery.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug.
Check the battery
lead connections,
and have a Yamaha
dealer charge the
battery if necessary.
2. BatteryThe battery is good.
The engine does not
start.
Check the ignition.
3. IgnitionWet
Dry
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.
The engine does not
start.
Check the
compression.Have a Yamaha
dealer check the
vehicle.
Remove the spark
plug and check
the electrodes.
Operate the electric
starter.
Operate the electric
starter.
Check the fuel level
in the fuel tank.
4. Compression
UBV3E0E0.book Page 40 Monday, September 26, 2016 3:42 PM

Scooter care and stora ge
7-2
7
structed
. Also, thorou ghly rinse
the area off with water, immed i-
ately dry it, an d then apply a cor-
rosion protection spray.
 Improper cleanin g can damag e
plastic parts (such as cowlin gs,
panels, win dshield s, hea dlig ht
lenses, meter lenses, etc.) an d
the mufflers. Use only a soft,
clean cloth or spon ge with wa-
ter to clean plastic. However, if
the plastic parts cannot be thor-
ou ghly cleaned with water, di-
lute d mil d d eter gent with water
may be used . Be sure to rinse
off any d etergent resi due usin g
plenty of water, as it is harmful
to plastic parts.
 Do not use any harsh chemical
prod ucts on plastic parts. Be
sure to avoi d usin g cloths or
spon ges which have b een in
contact with stron g or a brasive
cleanin g prod ucts, solvent or
thinner, fuel ( gasoline), rust re-
movers or inhi bit
ors, brake flui d,
antifreeze or electrolyte.
 Do not use hi gh-pressure wash-
ers or steam-jet cleaners since
they cause water seepag e and
d eterioration in the followin g ar-
eas: seals (of wheel an d swin g-
arm bearin gs, fork an d b rakes),
electric components (couplers,
connectors, instruments,
switches an d li ghts), breather
hoses an d vents.
 For scooters equipped with a
win dshiel d: Do not use strong
cleaners or har d spon ges as
they will cause dullin g or
scratching . Some cleanin gcompoun
ds for plastic may
leave scratches on the win d-
shiel d. Test the pro duct on a
small hidden part of the win d-
shiel d to make sure that it does
not leave any marks. If the win d-
shiel d is scratche d, use a quality
plastic polishin g compoun d af-
te

r washin g.
After normal use
Remove dirt with warm water, a mild
detergent, and a soft, clean sponge,
and then rinse thoroughly with clean
water. Use a toothbrush or bottlebrush
for hard-to-reach areas. Stubborn dirt
and insects will come off more easily if
the area is covered with a wet cloth for
a few minutes before cleaning.
After riding in the rain, near the sea, or
on salt-sprayed roads
Since sea salt or salt sprayed on roads
during winter are extremely corrosive
in combination with water, carry out
the following steps after each ride in
the rain, near the sea, or on salt-
sprayed roads.
TIP
Salt sprayed on roads in the winter
may remain well into spring.
1. Clean the scooter with cold water
and a mild detergent after the en-
gine has cooled down. NOTICE:
Do not use warm water since it
increases the corrosive action
of the salt.
[ECA10792]
2. Apply a corrosion protection spray on all metal, including chrome-
and nickel-plated, surfaces to pre-
vent corrosion.
UBV3E0E0.book Page 2 Monday, September 26, 2016 3:42 PM

Scooter care and stora ge
7-4
7
EAU36564
Stora ge
Short-term
Always store your scooter in a cool, dry
place and, if necessary, protect it
against dust with a porous cover. Be
sure the engine and the exhaust sys-
tem are cool before covering the
scooter.
NOTICE
ECA10821
 Storin g the scooter in a poorly
ventilate d room or coverin g it
with a tarp, while it is still wet,
will allow water an d humi dity to
seep in an d cause rust.
 To prevent corrosion, avoi d
d amp cellars, sta bles ( because
of the presence of ammonia)
an d areas where stron g chemi-
cals are store d.
Lon g-term
Before storing your scooter for several
months: 1. Follow all the instructions in the “Care” section of this chapter.
2. Fill up the fuel tank and add fuel stabilizer (if available) to prevent
the fuel tank from rusting and the
fuel from deteriorating.
3. Perform the following steps to protect the cylinder, piston rings,
etc. from corrosion.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.)
e. Remove the spark plug cap from the spark plug, and then
install the spark plug and the
spark plug cap. WARNING! To
prevent damag e or injury
from sparkin g, make sure to
g roun d the spark plu g elec-
tro des while turnin g the en-
g ine over.
[EWA10952]
4. Lubricate all control cables and
the pivoting points of all levers and
pedals as well as of the side-
stand/centerstand.
5. Check and, if necessary, correct the tire air pressure, and then lift
the scooter so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
6. Cover the muffler outlet with a plastic bag to prevent moisture
from entering it.
7. Remove the battery and fully charge it. Store it in a cool, dry
place and charge it once a month.
Do not store the battery in an ex-
cessively cold or warm place [less
than 0 °C (30 °F) or more than 30
°C (90 °F)]. For more information
on storing the battery, see page
6-30.
UBV3E0E0.book Page 4 Monday, September 26, 2016 3:42 PM

Specifications
8-1
8
Dimensions:
Overall length:1955 mm (77.0 in)
Overall width:
740 mm (29.1 in)
Overall height: 1115 mm (43.9 in)
Seat height: 765 mm (30.1 in)
Wheelbase:
1350 mm (53.1 in)
Ground clearance: 135 mm (5.31 in)
Minimum turning radius: 2.0 m (6.56 ft)
Wei ght:
Curb weight:
127 kg (280 lb)
Engine:
Combustion cycle:
4-stroke
Cooling system:
Liquid cooled
Valve train: SOHC
Number of cylinders: Single cylinder
Displacement:
125 cm³ (GPD125-A)
155 cm³ (GPD150-A)
Bore × stroke:
52.0 × 5 8 . 7 m m (2 . 0 5 × 2.31 in) (GPD125-A)
58.0 × 5 8 . 7 m m (2 . 2 8 × 2.31 in) (GPD150-A)
Compression ratio:
10.5 : 1 (GPD150-A)
11.2 : 1 (GPD125-A)
Starting system:
Electric starter
Lubrication system: Wet sump
Engine oil:
Recommended brand:
YAMALUBE
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-30 type SE or higher or
Gear oil SAE 85W GL-3
Quantity: 0.15 L (0.16 US qt, 0.13 Imp.qt)
Coolant quantity:
Coolant reservoir (up to the maximum level
mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
Radiator (including all routes):
0.46 L (0.49 US qt, 0.40 Imp.qt)
Air filter:
Air filter element:Oil-coated paper element
Fuel:
Recommended fuel:Regular unleaded gasoline (Gasohol [E10]
acceptable)
Fuel tank capacity: 6.6 L (1.7 US gal, 1.5 Imp.gal)
Fuel reserve amount: 1.4 L (0.37 US gal, 0.31 Imp.gal)
Fuel injection:
Throttle body:ID mark:
2DS1 00
Spark plu g(s):
Manufacturer/model:
NGK/CPR8EA-9
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Clutch:
Clutch type:Dry, centrifugal, shoe
Drivetrain:
Primary reduction ratio:1.000
Final drive: Gear
Secondary reduction ratio:
10.208 (56/16 x 35/12)
Transmission type: V-belt automatic
Chassis:
Frame type:
Underbone
UBV3E0E0.book Page 1 Monday, September 26, 2016 3:42 PM

Consumer information
9-2
9
EAU69910
Diagnostic connector
The diagnostic connector is located as
shown.
EAU74701
Vehicle data recor din g
This model’s ECU stores certain vehi-
cle data to assist in the diagnosis of
malfunctions and for research and de-
velopment purposes. This data will be
uploaded only when a special Yamaha
diagnostic tool is attached to the vehi-
cle, such as when maintenance checks
or service procedures are performed.
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
Yamaha will not disclose this data to a third party except:  With the consent of the vehicle
owner
 Where obligated by law
 For use by Yamaha in litigation
 For general Yamaha-conducted
research purposes when the data
is not related to an individual vehi-
cle nor owner
1. FI diagnostic connector
1
UBV3E0E0.book Page 2 Monday, September 26, 2016 3:42 PM

10-1
10
Index
A
ABS ....................................................... 3-11
ABS warning light ................................... 3-3
Acceleration and deceleration ................ 5-3
Air filter and V-belt case air filter
elements ............................................. 6-17
Auxiliary light bulb, replacing ................ 6-34
B
Battery .................................................. 6-30
Brake fluid, changing ............................ 6-26
Brake fluid level, checking .................... 6-25
Brake lever, front .................................. 3-10
Brake lever, rear.................................... 3-11
Brake levers, lubricating ....................... 6-28
Brake light ............................................. 6-35
Braking.................................................... 5-3
C
Cables, checking and lubricating ......... 6-27
Care ........................................................ 7-1
Catalytic converter ................................ 3-15
Centerstand and sidestand, checking and lubricating .................... 6-28
Coolant ................................................. 6-13
Coolant temperature warning light ......... 3-3
D
Data recording, vehicle ........................... 9-2
Diagnostic connector.............................. 9-2
Dimmer switch ........................................ 3-9
E
Engine break-in....................................... 5-4
Engine oil and oil strainer...................... 6-10
Engine serial number .............................. 9-1
Engine trouble warning light ................... 3-3
F
Final transmission oil ............................ 6-12
Front and rear brake lever free play, checking ............................................. 6-23
Front and rear brake pads, checking.... 6-24
Front fork, checking .............................. 6-29
Fuel ....................................................... 3-13
Fuel consumption, tips for reducing ....... 5-4
Fuel tank cap ........................................ 3-12
Fuel tank overflow hose ........................ 3-15
Fuses, replacing.................................... 6-32
H
Handlebar switches ................................ 3-9
Headlight............................................... 6-33
High beam indicator light........................ 3-3
Horn switch ........................................... 3-10
I
Identification numbers ............................ 9-1
Ignition circuit cut-off system............... 3-18
Indicator lights and warning lights ......... 3-3
K
Keyhole shutter ...................................... 3-2
M
Main switch/steering lock....................... 3-1
Maintenance and lubrication, periodic ... 6-4
Maintenance, emission control system.................................................. 6-3
Matte color, caution ............................... 7-1
Model label ............................................. 9-1
Multi-function meter unit ........................ 3-4
P
Panels, removing and installing.............. 6-7
Parking ................................................... 5-5
Part locations ......................................... 2-1
S
Safe-riding points ................................... 1-5
Safety information .................................. 1-1
Seat ...................................................... 3-16
Sidestand ............................................. 3-17
Spark plug, checking ............................. 6-9
Specifications ......................................... 8-1
Starting off.............................................. 5-2
Starting the engine ................................. 5-1
Start switch .......................................... 3-10
Steering, checking................................ 6-29
Storage ................................................... 7-4
Storage compartments ........................ 3-16
T
Taillight bulb, replacing ........................ 6-35
Throttle grip and cable, checking and lubricating .................... 6-27
Throttle grip free play, checking........... 6-19
Tires ...................................................... 6-20
Tool kit.................................................... 6-2
Troubleshooting ................................... 6-39
Troubleshooting charts ........................ 6-40
Turn signal indicator lights ..................... 3-3
Turn signal light bulb (front), replacing ............................................ 6-37
Turn signal light bulb (rear), replacing ............................................ 6-38
Turn signal switch .................................. 3-9
V
Valve clearance .................................... 6-20
V-belt, checking ................................... 6-26
Vehicle identification number ................. 9-1
UBV3E0E0.book Page 1 Monday, September 26, 2016 3:42 PM