YAMAHA NMAX 155 2021 Repair Manual

Operation and important ri din g points
8-2
8
EAU86741
Startin g the en gineThe ignition circuit cut-off system will
enable starting only when the side-
stand is up.
To start the engine1. Turn the main switch on.
2. Confirm the indicator and warning light(s) come on for a few sec-
onds, and then go off. (See page
6-1.)TIPDo not start the engine if the en-
gine trouble warning light remains
on.
 The ABS warning light should
come on and stay on until the ve-
hicle reaches a speed of 10 km/h
(6 mi/h).NOTICE
ECA24110
If a warnin g or in dicator li ght does
not work as d escribed a bove, have a
Yamaha dealer check the vehicle.3. Close the throttle completely.
4. While applying the front or rear
brake, push the start switch. 5. Release the start switch when the
engine starts, or after 5 seconds.
Wait 10 seconds before pressing
the switch again to allow battery
voltage to restore.
NOTICE
ECA11043
For maximum en gine life, never ac-
celerate har d when the en gine is
col d!
EAU45093
Startin g off1. While pulling the rear brake lever
with your left hand and holding the
grab bar with your right hand,
push the scooter off the center-
stand.
2. Sit astride the seat, and then ad- just the rear view mirrors.
3. Switch the turn signals on.
4. Check for oncoming traffic, and then slowly turn the throttle grip
(on the right) in order to take off.
5. Switch the turn signals off.1. Grab bar
1
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Operation and important rid ing points
8-3
8
EAU16782
Acceleration an d d ecelerationThe speed can be adjusted by opening
and closing the throttle. To increase
the speed, turn the throttle grip in di-
rection (a). To reduce the speed, turn
the throttle grip in direction (b).
EAU60650
Brakin g
WARNING
EWA17790
Avoi d b rakin g har d or su ddenly
(especially when leanin g over to
one si de), otherwise the vehicle
may skid or overturn.
 Railroa d crossin gs, streetcar
rails, iron plates on road con-
struction sites, an d manhole
covers become extremely slip-
pery when wet. Therefore, slow
d own when approachin g such
areas an d cross them with cau-
tion.
 Keep in min d that b raking on a
wet road is much more difficult.
 Ride slowly d own a hill, as brak-
in g d ownhill can be very d iffi-
cult.1. Close the throttle completely.
2. Apply both front and rear brakes simultaneously while gradually in-
creasing the pressure.
EAU16821
Tips for re ducin g fuel con-
sumptionFuel consumption depends largely on
your riding style. Consider the follow-
ing tips to reduce fuel consumption:
 Avoid high engine speeds during
acceleration.
 Avoid high engine speeds with no
load on the engine.
 Turn the engine off instead of let-
ting it idle for an extended length
of time (e.g., in traffic jams, at traf-
fic lights or at railroad crossings).
(b)
(a)
ZAUM0199
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Operation and important ri din g points
8-4
8
EAUW4891
Parkin g When parking, turn off the Stop and
Start System and then stop the engine.
After turning off the main switch, be
sure to turn off the smart key and take
it with you.
WARNING
EWA18840
 Since the en gine an d exhaust
system can b ecome very hot,
park in a place where pe destri-
ans or chil dren are not likely to
touch them an d b e burne d.
 Do not park on a slope or on soft
groun d, otherwise the vehicle
may overturn, increasin g the
risk of a fuel leak an d fire.
 Do not park near grass or other
flamma ble materials which
mi ght catch fire.
 If the Stop an d Start System is
left turne d on, the b attery could
b ecome dischar ged an d it may
not be possi ble to restart the
en gine due to insufficient b at-
tery volta ge.
TIPEven when the vehicle is parked in a lo-
cation partitioned by a fence or the
glass window of a shop, if the smart
key is within operating range, other
people will be able to start the engine
and operate the vehicle. Please turn
the smart key off when leaving the ve-
hicle. (See page 3-8.)
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Periodic maintenance an d a djustment
9-1
9
EAU17246
Periodic inspection, adjustment, and
lubrication will keep your vehicle in the
safest and most efficient condition
possible. Safety is an obligation of the
vehicle owner/operator. The most im-
portant points of vehicle inspection,
adjustment, and lubrication are ex-
plained on the following pages.
The intervals given in the periodic
maintenance charts should be simply
considered as a general guide under
normal riding conditions. However, de-
pending on the weather, terrain, geo-
graphical location, and individual use,
the maintenance intervals may need to
be shortened.
WARNING
EWA10322
Failure to properly maintain the vehi-
cle or performin g maintenance ac-
tivities incorrectly may increase
your risk of injury or death durin g
service or while usin g the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha d ealer perform
service.
WARNING
EWA15123
Turn off the en gine when performin g
maintenance unless otherwise
specified .
 A runnin g en gine has movin g
parts that can catch on body
parts or clothin g an d electrical
parts that can cause shocks or
fires.
 Runnin g the en gine while ser-
vicin g can lead to eye injury,
b urns, fire, or car bon monoxi de
poisonin g – possi bly lea din g to
d eath. See pag e 1-3 for more in-
formation a bout car bon monox-
i d e.
WARNING
EWA15461
Brake discs, calipers, drums, and
linin gs can b ecome very hot d uring
use. To avoi d possi ble burns, let
b rake components cool before
touchin g them.
EAU85230
Tool kitThe tool kit is in the location shown.
The information included in this manual
and the tools provided in the tool kit are
intended to assist you in the perfor-
mance of preventive maintenance and
minor repairs. However, a torque
wrench and other tools are necessary
to perform certain maintenance work
correctly.TIPIf you do not have the tools or experi-
ence required for a particular job, have
your Yamaha dealer perform it for you.1. Tool kit
1
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Periodic maintenance an d a djustment
9-2
9
EAU71021
TIP The annual checks must be performe d every year, except if a distance- based maintenance is performe d in-
stea d.
 From 30000 km (17500 mi), repeat the maintenance intervals starting from 6000 km (3500 mi).
 Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and tech-
nical skills.
EAU71041
Perio dic maintenance chart for the emission control systemNO. ITEM CHECK OR MAINTENANCE JOB ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
1 *Fuel line • Check fuel hoses for cracks or
damage.
• Replace if necessary. 
2 Spark plu g• Check condition.
• Adjust gap and clean.

•Replace. 
3 *Valve clearance • Check and adjust. 
4 *Fuel injection • Check engine idle speed. 
5 *Exhaust system • Check for leakage.
• Tighten if necessary.
• Replace gasket if necessary. 
6 *Evaporative emis-
sion control system • Check control system for dam-
age.
• Replace if necessary. 
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Periodic maintenance an d a djustment
9-3
9
EAU71342
General maintenance an d lu brication chartNO. ITEM CHECK OR MAINTENANCE JOB ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
1 *Dia
gnostic system
check • Perform dynamic inspection us-
ing Yamaha diagnostic tool.
• Check the error codes. 
2 *Air filter element • Replace. Every 18000 km (10500 mi)
3 Air filter case check
hose • Clean.

4 *V-
belt case air filter
element • Clean.
• Replace if necessary.

5 *Battery • Check voltage.
• Charge if necessary.

6 *Front brake • Check operation, fluid level, and
for fluid leakage.
• Replace brake pads if necessary. 
7 *Rear brake • Check operation, fluid level, and
for fluid leakage.
• Replace brake pads if necessary. 
8 *Brake hose • Check for cracks or damage.

• Replace. Every 4 years
9 *Brake flui d • Change. Every 2 years
10 *Wheels • Check runout and for damage.
• Replace if necessary.

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Periodic maintenance an d a djustment
9-4
9
11 *Tires • Check tread depth and for dam-
age.
• Replace if necessary.
• Check air pressure.
• Correct if necessary. 
12 *Wheel bearin gs • Check bearing for looseness or
damage. 
13 *Steerin g b earin gs • Check bearing assemblies for
looseness. 
• Moderately repack with lithium- soap-based grease. 
14 *Chassis fasteners • Make sure that all nuts, bolts and
screws are properly tightened. 
15 Front an
d rear
b rake lever pivot
shaft • Lubricate with silicone grease.

16 Si
destan d, center-
stan d • Check operation.
• Lubricate with lithium-soap-
based grease. 
17 *Sidestan d switch • Check operation and replace if
necessary. 
18 *Front fork • Check operation and for oil leak-
age.
• Replace if necessary. 
19 *Shock a
bsor ber as-
sem blies • Check operation and for oil leak-
age.
• Replace if necessary. 
NO. ITEM CHECK OR MAINTENANCE JOB
ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 2400
0 km

(14000 mi)
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Periodic maintenance an d a djustment
9-5
9
20 En gine 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 *Coolin g 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 an
d rear
b rake switches • Check operation.

26 *Movin
g parts an d
cab les • Lubricate.

27 *Throttle
grip hous-
in g an d cab le • Check operation and free play.
• Adjust the throttle cable free play
if necessary.
• Lubricate the throttle grip housing and cable. 
28 *Li
ghts, si gnals an d
switches • Check operation.
• Adjust headlight beam.

NO. ITEM CHECK OR MAINTENANCE JOB
ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 1
8000 km

(10500 mi) 24000 km
(14000 mi)
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Periodic maintenance an d a djustment
9-6
9
EAU72790
TIP Engine air filter and V-belt air filter
• This model’s engine air filter is equipped with a disposable oil-coated paper element, which must not be cleaned with compressed air to avoid damaging it.
• The engine air filter element needs to be replaced and the V-belt air filter element needs to be serviced more fre-
quently when riding in unusually wet or dusty areas.
 Hydraulic brake service
• After disassembling the brake master cylinders and calipers, always change the fluid. Regularly check the brake fluid levels and fill the reservoirs as required.
• Every two years replace the internal components of the brake master cylinders and calipers, and change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.
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Periodic maintenance an d a djustment
9-7
9
EAU18773
Removin g an d installin g pan-
elsThe panels shown need to be removed
to perform some of the maintenance
jobs described in this chapter. Refer to
this section each time a panel needs to
be removed and installed.
EAUN2600
Panel A
To remove the panel1. Remove the screws. 2. Extend the right passenger foot-
rest, and then pull the panel out-
ward.
To install the panel
1. Place the panel in the original po- sition, and then install the screws. 2. Retract the right passenger foot-
rest to its original position.
Panel B
To remove the panel
1. Remove panel A.
2. Remove the quick fasteners and the bolt.
1. Panel A
2. Panel B
3. Panel C
3
1
2
1. Panel A
2. Screw
1
2
1. Panel B
2. Quick fastener
1
2
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