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EAUS1090
Cleaning the air filter
element
The air filter element should be clea-
ned at the intervals specified in the
periodic maintenance and lubrication
chart. Clean the air filter element more
frequently if you are riding in unu-
sually wet or dusty areas.
1. Lid from the air filter box
2. Screw
3. Screw
1. Remove the screw clamp and the
screws that fasten the air filter
case to the crankcase.
1. Lid from the air filter box
2. Screws (x 3)
2. Remove the air filter case cover
by removing the screws.
3. Pull the air filter element out.
4. Clean the air filter element with
solvent, and then squeeze the
remaining solvent out.
1. The air filter
EWA10430
s s
WARNING
Use only a dedicated parts clea-
ning solvent. To avoid the risk of
fire or explosion, do not use gasoli-
ne or solvents with a low flash
point.
ECA10510
CAUTION
To avoid damaging the foam mate-
rial, handle it gently and carefully,
and do not twist or wring it.
5. Apply oil of the recommended
type to the entire surface of the
sponge material, and then sque-
eze the excess oil out.
NOTE:
The air filter element should be wet
but not dripping.
6. Insert the element into the air fil-
ter case.
Recommended oil:
Engine oil
6
PERIODIC MAINTENANCE AND MINOR REPAIR
6-8
12
3
1 2
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EAU32343
Checking the front brake
fluid level
1. Minimum level
Insufficient brake fluid may allow air
to enter the brake system, possibly
causing it to become ineffective.
Before riding, check that the brake
fluid is above the minimum level mark
and replenish if necessary. A low bra-
ke fluid level may indicate worn brake
pads and/or brake system leakage. If
the brake fluid level is low, be sure to
check the brake pads for wear and
the brake system for leakage.Observe these precautions:
When checking the fluid level,
make sure that the top of the
master cylinder is level by turning
the handlebars.
Use only the recommended qua-
lity brake fluid, otherwise the rub-
ber seals may deteriorate, cau-
sing leakage and poor braking
performance.
Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking performan-
ce.
Be careful that water does not
enter the master cylinder when
refilling. Water will significantly
lower the boiling point of the fluid
and may result in vapor lock.
Brake fluid may deteriorate pain-
ted surfaces or plastic parts.
Always clean up spilled fluid
immediately.
As the brake pads wear, it is nor-
mal for the brake fluid level to
gradually go down. However, if
the brake fluid level goes down
suddenly, have a Yamaha dealer
check the cause.
EAU22720
Changing the brake fluid
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the NOTE after the periodic mainte-
nance and lubrication chart. In addi-
tion, have the oil seals of the brake
master cylinder and caliper as well as
the brake hose replaced at the inter-
vals listed below or whenever they are
damaged or leaking.
Oil seals: Replace every two
years.
Brake hose: Replace every four
years.
EAU23100
Checking and lubricating the
cables
The operation of all control cables
and the condition of the cables
should be checked before each ride,
Recommended brake fluid:
DOT 4
6
PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
MIN
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DimensionsOverall length
1740 mm
Overall width
675 mm
Overall height
1065 mm
Seat height
770 mm
Wheelbase
1210 mm
Ground clearance
132 mm
WeightWith oil and fuel
CS50 80.5 kg
CS50Z 83.7 kg
EngineEngine type
CS50 Air cooled 2-stroke
CS50Z Liquid cooled 2-stroke
Cylinder arrangement
Forward-inclined single cylinder
Displacement
49.2 cm3
Bore x stroke
40.0 x 39.2 mm
Compression ratio
CS50 10.20 :1
CS50Z 11.40 :1
Starting system
Electric starter and kickstarter
Lubrication system
Separate lubrication (Yamaha autolube)Type
YAMALUBE 2-cycle oil or 2-stroke engine
oil
Engine oil quantityQuantity
1.4 L
Transmission oilType
YAMALUBE 4 (10W30) or SAE10W30
type SE motor oil
Oil change quantity
0.10 L
Air filter element
Wet element
Fuel
Recommended fuel
Regular unleaded gasoline
Fuel tank capacity
5.5 L
CarburetorManufacturer
CS50 DELLORTO GURTNER
CS50Z DELLORTO
Type x quantity
CS50 PHVA 12 ZS/1 PY 12/1
CS50Z PHVA 12 ZS/1
Spark plug(s)Manufacturer/model
NGK/BR8HS
Spark plug gap
0.6-0.7 mm
Clutch type
Dry, centrifugal automatic
TransmissionPrimary reduction system
Helical gear
Primary reduction ratio
52/13 (4.000)
Secondary reduction system
Spur gear
Secondary reduction ratio
CS50 42/13 (3.230)
CS50Z 43 x 13 (3.310)
Transmission type
Single speed automatic
Operation
Centrifugal automatic type
ChassisCaster angle
25.00 degree
Trail
80.0 mm
Front tireSize
110/70-12 47L
Rear tireSize
120/70-12 51L 130/70-12 56L
Maximum load
CS50 161 kg
CS50Z 158 kg
Tire air pressure (measured on cold
tires)
Front
175 kPa
Rear
200 kPa
8
SPECIFICATIONS
8-1
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Front wheelRim size
MT 2.75X12
Rear wheelRim size
MT 3.00X12
Front brakeType
Single disc brake
Operation
Right hand operation
Recommended fluid
DOT 4
Rear brakeType
Drum brake
Operation
Left hand operation
Front suspensionType
Telescopic fork
Spring/shock absorber type
Coil spring/oil damper
Wheel travel
70.0 mm
Rear suspensionType
Unit swing
Spring/shock absorber type
Coil spring/oil damper
Wheel travel
60.0 mm
Electrical systemIgnition systemCDI
Charging system
Flywheel magneto
BatteryModel
GT4L-BS
Voltage, capacity
12 V, 4.0 Ah
Bulb voltage, wattage x quantityHeadlight
12 V, 35 W/35.0 W x 1
Tail/brake light
12 V, 21.0 W/5.0 W x 1
Front turn signal light
12 V, 16.0 W x 2
Rear turn signal light
12 V, 10.0 W x 2
Meter lighting
12 V, 1.2 W x 2
Oil level warning light
LED
Fuel level warning light
NONE
FusesMain fuse
7.5 A
8
SPECIFICATIONS
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