Page 14 of 74
DESCRIPTION
2-1
2
EAU10410
Left view
NS50N
NS50N
12
34
5
6
7
1. Coolant reservoir cap (page 6-9)
2. Storage compartment (page 3-12)
3. Air filter element (page 6-10)
4. Kickstarter (page 3-11)
5. Final transmission oil filler cap (page 6-8)
6. Shock absorber assembly spring preload adjusting ring (page 3-13)
7. Final transmission oil drain bolt (page 6-8)U1PHE0E0.book Page 1 Wednesday, August 29, 2012 4:42 PM
Page 31 of 74

FOR YOUR SAFETY – PRE-OPERATION CHECKS
4-1
4
EAU15596
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
EWA11151
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.3-9
2-stroke engine oil Check oil level in oil tank.
If necessary, add recommended oil to specified level.
Check vehicle for oil leakage.3-10
Final transmission oil Check vehicle for oil leakage. 6-8
Coolant Check coolant level in reservoir.
If necessary, add recommended coolant to specified level.
Check cooling system for leakage.6-9
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.6-14, 6-15, 6-15
U1PHE0E0.book Page 1 Wednesday, August 29, 2012 4:42 PM
Page 45 of 74

PERIODIC MAINTENANCE AND ADJUSTMENT
6-9
6
EAU20070
Coolant The 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.
EAUM2102
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.TIP●
The coolant level must be checked
on a cold engine since the level
varies with engine temperature.
●
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 through
the check window.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
cowling A. (See page 6-6.)
4. Open the reservoir cap, and then
add coolant to the maximum level
mark. WARNING! Remove only
the coolant reservoir cap. Never
attempt to remove the radiator
cap when the engine is hot.
[EWA15161]
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
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.
[ECA10472]
5. Close the reservoir cap, and then
install the cowling.
1. Maximum level mark
2. Minimum level mark
1
2
ZAUM0591
1. Coolant reservoir cap
Coolant reservoir capacity:
0.25 L (0.26 US qt, 0.22 Imp.qt)1ZAUM0274
U1PHE0E0.book Page 9 Wednesday, August 29, 2012 4:42 PM
Page 63 of 74

PERIODIC MAINTENANCE AND ADJUSTMENT
6-27
6 Engine overheating
WARNING
EWA10400
●
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.
●
After removing the radiator cap retaining bolt, 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 coolant
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.
U1PHE0E0.book Page 27 Wednesday, August 29, 2012 4:42 PM
Page 68 of 74

SPECIFICATIONS
8-1
8
Dimensions:Overall length:
1870 mm (73.6 in)
Overall width:
NS50 700 mm (27.6 in)
NS50N 725 mm (28.5 in)
Overall height:
NS50 1155 mm (45.5 in)
NS50N 1115 mm (43.9 in)
Seat height:
815/930 mm (32.1/36.6 in)
Wheelbase:
1275 mm (50.2 in)
Ground clearance:
130 mm (5.12 in)
Minimum turning radius:
2000 mm (78.7 in)Weight:Curb weight:
97 kg (214 lb)Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Single cylinder
Displacement:
49 cm³
Bore × stroke:
40.0 × 39.2 mm (1.57 × 1.54 in)
Compression ratio:
11.50–12.50 : 1
Starting system:
Electric starter and kickstarterLubrication system:
Separate lubrication (Yamaha autolube)
Engine oil:Type:
YAMALUBE 2S or 2-stroke engine oil
(JASO FC grade) or (ISO EG-C or EG-D
grade)
Engine oil quantity:
Quantity:
1.40 L (1.48 US qt, 1.23 Imp.qt)Final transmission oil:Type:
SAE 10W-30 type SE motor oil
Quantity:
0.11 L (0.12 US qt, 0.10 Imp.qt)Cooling system:Coolant reservoir capacity (up to the
maximum level mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
Radiator capacity (including all routes):
1.20 L (1.27 US qt, 1.06 Imp.qt)Air filter:Air filter element:
Wet elementFuel:Recommended fuel:
Premium unleaded gasoline only
Fuel tank capacity:
7.0 L (1.85 US gal, 1.54 Imp.gal)
Fuel reserve amount:
1.0 L (0.26 US gal, 0.22 Imp.gal)Carburetor:Type × quantity:
PHVA 12 ZS x 1
Spark plug(s):Manufacturer/model:
NGK/BR8HS
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)Clutch:Clutch type:
Dry, centrifugal automaticTransmission:Primary reduction ratio:
1
Final drive:
Gear
Secondary reduction ratio:
52/13 × 43/14 (12.286)
Transmission type:
V-belt automatic
Operation:
Centrifugal automatic typeChassis:Frame type:
Underbone
Caster angle:
27.00 °
Trail:
87 mm (3.4 in)Front tire:Type:
Tubeless
Size:
120/70-13 53P(Michelin)
53L(SAVA,Metzeler)
Manufacturer/model:
MICHELIN/POWER PURE SC
U1PHE0E0.book Page 1 Wednesday, August 29, 2012 4:42 PM