Page 32 of 76

FOR YOUR SAFETY – PRE-OPERATION CHECKS
4-2
4
EAU15605
Pre-operation check list
ITEM CHECKS PAGE
• Check fuel level in fuel tank.
Fuel• Refuel if necessary.3-8
• Check fuel line for leakage.
• Check oil level in oil tank.
2-stroke engine oil• If necessary, add recommended oil to specified level. 3-10
• Check vehicle for oil leakage.
Final transmission oil• Check vehicle for oil leakage. 6-7
• Check coolant level in reservoir.
Coolant (CS50Z)• If necessary, add recommended coolant to specified level. 6-8
• Check cooling system for leakage.
• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
Front brake• Replace if necessary. 6-13, 6-14, 6-15
• Check fluid level in reservoir.
• If necessary, add recommended brake fluid to specified level.
• Check hydraulic system for leakage.
• Check operation.
Rear brake• Lubricate cable if necessary.
• Check lever free play.6-13, 6-14
• Adjust if necessary.
• Make sure that operation is smooth.
Throttle grip• Check cable free play.
• If necessary, have Yamaha dealer adjust cable free play 6-10, 6-16
and lubricate cable and grip housing.
• Check for damage.
Wheels and tires• Check tire condition and tread depth.
• Check air pressure.6-11, 6-12
• Correct if necessary.
Page 41 of 76

PERIODIC MAINTENANCE AND ADJUSTMENT
6-4
6
ODOMETER READING
CHECK OR ANNUAL
NO. ITEM MAINTENANCE JOB
1000 km 6000 km 12000 km 18000 km 24000 kmCHECK
(600 mi) (3500 mi) (7000 mi) (10500 mi) (14000 mi)
• Check coolant level and vehicle
19 *Cooling system
for coolant leakage.√√√ √√(CS50Z)
• Change. Every 3 years
20Final transmission • Check vehicle for oil leakage.
oil• Change.√√ √√ √ √
21 *V-belt• Replace. Every 10000 km (6000 mi)
22 *Front and rear
brake switches• Check operation.√√ √√ √ √
23Moving parts
and cables• Lubricate.√√√ √√
• Check operation and free play.
Throttle grip• Adjust the throttle cable free play
24 * if necessary.√√√ √√
housing and cable
• Lubricate the throttle grip
housing and cable.
25 *Lights, signals and • Check operation.
switches• Adjust headlight beam.√√ √√ √ √
EAUM2070
TIP
●The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
●Hydraulic brake service
• Regularly check and, if necessary, correct the brake fluid level.
• Every two years change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.
Page 46 of 76

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 coolant as soon as possi-
ble, otherwise the cooling sys-
tem will not be protected
against frost and corrosion. If
water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possi-
ble, otherwise the effective-
ness of the coolant will be
reduced.
[ECA10472]
1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level mark
5. Close the reservoir cap, and then
install the cowling.
EAU33031
Changing the coolant
The coolant must be changed at the
intervals specified in the periodic
maintenance and lubrication chart.
Have a Yamaha dealer change the
coolant. WARNING! Never attempt
to remove the radiator cap when
the engine is hot.
[EWA10381]EAU40370
Air filter element
The air filter element must be cleaned
and replaced at the intervals specified
in the periodic maintenance and lubri-
cation chart. Have a Yamaha dealer
clean and replace the air filter ele-
ment.
Coolant reservoir capacity:
0.25 L (0.26 US qt, 0.22 Imp.qt)
1
2
3FULL
LOW
PERIODIC MAINTENANCE AND ADJUSTMENT
6-9
6
Page 64 of 76

Engine overheating (CS50Z)EWA10400
sWARNING
●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 his-
sing sound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
TIP
If 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.
PERIODIC MAINTENANCE AND ADJUSTMENT
6-27
6
Page 69 of 76

Dimensions:Overall length:
1740 mm (68.5 in)
Overall width:
675 mm (26.6 in)
Overall height:
1065 mm (41.9 in)
Seat height:
770 mm (30.3 in)
Wheelbase:
1210 mm (47.6 in)
Ground clearance:
132 mm (5.20 in)
Weight:With oil and fuel:
CS50/CS50M: 81.0 kg (178.6 lb)
CS50Z: 84.0 kg (185.2 lb)
Engine:CS50/CS50M: Air cooled 2-stroke
CS50Z: Liquid cooled 2-stroke
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
49.2 cm
3
Bore x stroke:
40.0 x 39.2 mm (1.57 x 1.54 in)
Compression ratio:
CS50: 11.60:1
CS50M: 10.10 :1
CS50Z: 11.40 :1
Starting system:
Electric starter and kickstarter
Lubrication system:
Separate lubrication (Yamaha autolube)Type:
YAMALUBE 2 or 2-stroke engine oil
Engine oil quantity:Quantity:
1.40 L (1.48 US qt, 1.23 Imp.qt)
Final transmission oil:Type:
SAE10W30 type SE motor oil
Quantity:
0.11 L (0.12 US qt) (0.10 Imp.qt)
Cooling system (CS50Z):Coolant reservoir capacity (up to the maxi-
mumlevel mark):
0.25 L (0.26 US qt) (0.22 Imp.qt)
Radiator capacity (including all routes):
0.91 L (0.96 US qt) (0.80 Imp.qt)
Air filter:Air filter element:
Wet element
Fuel:Recommended fuel:
Regular unleaded gasoline
Fuel tank capacity:
5.5 L (1.45 US gal, 1.21 Imp.gal)
Fuel reserve amount:
1.9 L (0.50 US gal, 0.42 Imp.gal)
Carburetor:Manufacturer:
GURTNER
Type x quantity:
PY12
Spark plug(s):Manufacturer/model:
CS50-CS50Z: NGK/BR8HS
CS50M: NGK/BPR4HS
Spark plug gap:
0.6-0.7 mm (0.024-0.028 in)
Clutch:Clutch type:
Dry, centrifugal automatic
Transmission:Primary reduction system:
Helical gear
Primary reduction ratio:
52/13 (4.000)
Secondary reduction system:
Spur gear
Secondary reduction ratio:
CS50: 42 x 13 (3.230)
CS50M: 45 x 12(3.750)
CS50Z: 43 x 13 (3.308)
Transmission type:
V-belt automatic
Operation:
Centrifugal automatic type
Chassis:Frame type:
Steel tube underbone
Caster angle:
25.00 º
Trail:
80.0 mm (3.15 in)
Front tire:Type:
Tubeless
SPECIFICATIONS
8-1
8