Yamaha QT50 User manual

OWNER'S MANUAL
LIT-11626-02 - 11
3L8 - 28199-11

SAFETY WARNINGS
1. Traffic regulations vary from state to
state. Study the regulations in your
state before riding this machine.
2. Never all
ow children to ride th is ma-
chine. Check
the tr af fic regul at ions in
your state regarding the mini
mum age
requirements
for a driver's licen se.
Abide by all state and local regulations.
3. This machine is a single-seater. It is
made for one rider only. Never ride
with
a passenger. Overloading will adversly
affect the machine's stabil ity . Do not
load the racks beyond their capaci ty .
The load capacity
of the front rack (car-
rier) is 3
kg (7 lbs). The load capacity" of
the rear rack (carrier) is 5 kg ( 11 lbs).
4. This bike is designed for on-road use
.only. It is not suitable for off-road use.
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5. Gasoline is highly flammable.
•
Always turn off the engine when re-
fuelling.
• Take care
not to spill any gasoline on
the engine or muffler when refuelling.
"' If any gasoline sp ills on the engine or
muf fl er , wipe it off immed i ately .
"' Never refuel while smoking or in the
vicinity of an open flame.
6. Always turn off the engine before leav-
ing the machine unattended.
7.
When transpor ting the machine in an-
ot her vehicl e, be sure it is kept upright
and that the fuel petcock is turned off .
If it should lean over, gasoline may leak
out of the carburetor or fuel tank .

8. The bike should always be on the center
stand when you start the engine. Check
the throttle grip a few times before
starting off. The engine speed should
slow down when the throttle is closed.
9. If you should swallow some gasoline or
inhale to many gasoline vapors, see
your doctor immediately.
If any gasoline
spills on your skin or clothing,
im-
mediately wash with soap and water
and change your clothes.
10. Do
not run the engine in a closed, un-
ventilated place. Exhaust gases are
harmful.
SAFETY RIDING POINTS
1. Give a clear signal in the following
instances:
Turning
left
Turning right
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Stopping or slow in g down
2. Braking ca n be extremely difficult on a
wet road. Avoid hard braking, the ma-
chine could sl ide. App ly the brakes
slowly when stopping on a wet surface.
3. Sl
ow down as you approach a corner or
turn. Once you have completed a turn,
accelerate sl
ow l y.
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4. Be care fu l whe n passing parked cars. A
dr iver might not see you and open a
door in your path.
5. Street car rails, iron plates on
road con-
struct ion sites, and man-hole covers be-
come extremely slippery when wet.
Slow down and cross them with cau-
ti on . Keep the machine upright. It could
slide
out from under you.
6. The brake
lining could get wet when
you wash the machine. After washing
the machine, check the brakes before
riding.
7.
Always wear a helmet, gloves, trousers
(tapered around
the cuff and ankle so
they do not flap), and a bright colored
jacket.

8. Do not carry too much luggage on the
bike. An overloaded machine is un-
stable. Refer
to page 1 for instructions
about carrying luggage. Use a strong
cord
to secure any luggage to the lug-
gage racks. A loose load will affect the
stability of the bike and could divert
your attention from the road.
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9. Never ride with just one hand on th e
handlebars.
Always ride with both
hands on the handlebars and both feet
on
the footrests.

INTRODUCTION
Please read th is manual carefully and completely before operating your
new bike. This manual will provide you with a good basic understanding of
the features, operation, and basic maintenance and inspection items of
this bike. If you have any questions regarding the operation or mainte-
nance of your bike, consu lt your Yamaha dealer.
NOTICE:~~~~ ~~~~~~~~~~~~~~~~
Some data in this manual may become outdated due to changes made
to this model in the future. If you have any question regarding this
manual or your bike, please consult your Yamaha dealer.
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NOTICE
Particularly important points are distinguished in this manual by the fol-
lowing notations:
NOTE: A NOTE provides key information to make procedures
easier
or clearer.
CAUTION: A CAUTION indicates special procedures that must be fol-
lowed to avoid damage to the bike.
WARNING: A WARNING indicates special procedures that must be
followed to avoid injury to a bike operator or person inspect-
ing
or repairing the bike.
OT50G OWNER'S MANUAL
FIRST PRINTING , APRIL, 1979
ALL RIGHTS RESERVED BY
YAMAHA MOTOR COMPANY, LTD., JAPAN
PRINTED IN JAPAN
LIT-11626-01 -96
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CONTENTS
MACHINE IDENTIFICATION ....................... 8
CONTROL FUNCTIONS................................ 9
PRE-OPERATION CHECKS.......................... 15
RIDING POINTS...... ... ..... ................ .. ........ .. .. .21
PERIODIC MAINTENANCE .. ........ .... . .... . .. ... 29
CONSUMER INFORMATION ...................... 32
WARRANTY INFORMATION .................. .... 34
SPECIFICATIONS .. . .. ............ ... . ... .. . ... ........ ... . 36
WIRING DIAGRAM . .. . .. ........ ... .... .. .. .. .. ........ .. 40
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MACHINE
IDENTIFICATION
Frame serial number
The frame se ri al number is stamped on the
front side f the steering head pipe.
1. Frame serial number
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Engine serial number
The engine serial num ber is stamped into the
left side of the engine lower of the cr ankcase.
1. Engine serial number
NOTE:- --- - ----- ----
The fir st three digits of these numbers are for
mode l identification; the remai ning digits
compr ise the unit produ ct ion number.

CONTROL FUNCTIONS
LEFT SIDE
RIGHT SIDE
I NSTRUMENTS
1. Front fork 12 . Front rack
2. Headlight
13 . Front wheel
3. Fuel tank 14 . Footrest
4. Oil tank
15 . Muff ler
5. Rear wheel
16 . Rear vi ew mirror
6. Rear shock absorber 17. Rear brake lever
7. Kick crank 18. L
eft handle switches
8. Tail/stop light 19. Speedometer
9. Flasher light
20 . Engine st
op switch
10. Rea r rack 21 . Fr
ont brake lever
11. Seat
22 . Throttle grip
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Main switch
OFF: Engine can not be started. Key can be
....-:
ON:
removed.
Oil warning l ight will come on with
the key in this position. For details of
the oil warning light. refer to the "Oil
warning light" on page 11.
Engine can be started
with the key in
this position. Key cannot be pulled out.
Taillight and meter lights always come
on automatically. Headlight
functions
onlv when the engine is running.
\
..-~:::.-~_;;;;;;;;:;:;=;:.::..::...-.. .. ~~
: •. · .. · .! : i~
J I t (IL -- 1
e YAMAHA !
fff"• f ti •
"HORN" switch
Press the button to sound the horn.
"TU RN SIGNAL" switch
This is a three way switch: the center posi-
toin is off. Turn to the "L" position for the l eft
flasher and to the "R" position for the right
flasher.
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"LIGHTS" switch (dimmer)
Turn to the "HI" position for the high beam
and
to the "LO" position for the low beam.
1 ... HORN"" switch 3.
"" LIGHTS "" switch (dimmer)
2
... TURN SIGNAL"" sw itch

"ENGINE STOP" switch
Make sure that the engine stop switch is
turned to "RUN" position. The engine switch
has been equipped to ensure safety in an
emergency·such as when the motorcycle is
upset
or trouble takes place in the throttle
system. The engine will not start or run when
the engine stop switch is turned to "OFF".
1. "EN GINE STOP" switch
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"OIL" warning light (Red)
The light comes on when the main switch
position is
.- or when there is little oil in the
oil tank during operation. If the oil warning
light comes on during operation, refill with
Yamalube 2-cycle Oil or an equivalent im-
mediately. When the tank is refilled, the oil
warning light will go
off .
NOTE:~~~~~~~~~~~~~
If the oil warning light will not come on while
the key is on the ".-" position. have your
Yamaha dealer
or other qualified service
establishment check it.
CAUTION:~~~~~~~~~--.
Do not run the bike until you know the
bike has enough oil.

"TURN" indicator light (Orange)
This light flashes when either turn indi-
cator is
ON.
"HIGH BEAM" indicator light (Blue)
This light comes on when the headlight
high beam is used.
1. "OIL " warning light
2. " TUAN " indic ato r light
Starter lev er
3. "H IGH BEAM" indicator light
4. Odometer
When starting a cold engine, turn the lever in
- 12-
the direction of the arrow. After a warm-up
run, turn the lever to its home position.
I
1. Starter lever
Fuel and oil tank
To supply fuel and/or engine oil, lift up the
seat. Then remove the fuel
tank filler cap
and/or oil tank fill er cap by turning them
counterclockwise.

Fuel tank capacity: 2.3 lit (0.6 U.S. gal)
Oil
tank capacity: 0.8 lit (0.8 U.S. qt)
1. Fuel tank cap 2. Oil
tank cap
CAUTION:~~~~~~~~~---,
If the oil tank level lowers during opera-
tion, the oil warning light comes on . Re-
fill the tank immediately. If not, engine
trouble could occur .
Fuel
petcock
The fuel petcock has three positions:
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ON: With the lever in this position, fuel will
fl ow. Normal ri ding is done with the
lever in this position.
OFF: With the lever in this position fuel wil l
not flow. Always set the lever in this
position when the engine is not run-
ning.
RES: If you run out of fuel while riding, turn
the lever to this position.
NOTE:~~~~~~~~~~~~~
Set the fuel petcock lever to "RES", and have
the fuel
tank filled as soon as possible.
After refilling, be sure to set the lever to
"ON". If you start off with the lever placed in
"RES", you may cont inue to ride unti l you
are completely run out of fuel, and you can-
not move at al l.

ON p os i tion
OFF posit i on
- 14-
RES po si tion
Front brake lever
The front brake lever is located on the right
handlebar; pull it toward the handlebar to
act ivate the front brake.

Rear brake lever
The rear brake lever is located on the left
handlebar; pull it t oward th e handlebar to ac-
tivate
th e rear brake.
- 1 5-
PRE-OPERATION CHECKS
Before riding this vehicle, check the fol-
lo
wing points:
NOTE: ~~ ~~ ~ ~~~ ~~~~
If any of the following items are not function-
ing proper ly, do not operate the vehicle unti l
the items have been inspected and repaired.
If necessary, ask or call your Yamaha dealer
or other qualified service establishment.
Fuel level
Make sure there is sufficient fuel in the tank.
Recommended fuel:
Regular leaded gasoline
Fu el tank ca pac ity : 2.3 lit (0.6 U.S. gal)

WARN I NG:------------.
Gasoline is inflammable:
•When refueling immediately after
operation, take special care not to
spill gasoline over the engine or muf-
fler.
•
Should you spill gasoline on the en-
gine or muffler, quickly wipe it off be-
fore starting the engine .
• When refueling , be sure to stop the
engine.
• Never attempt to refuel the bike while
smoking or near an open fire .
Engine oil level
Make sure there is sufficient oil in the oil
tank .
Recommended oil:
Yamalube 2-cycle Oi l or equivalent
Oil tank capacity: 0.8 l it (0.8 U.S.qt)
-16-
CAUTION:-----------.
If the oil tank level lowers during opera -
tion, the oil warning light comes on. Re-
fill the tank immediately. If not, engine
trouble could occur.
Brake (front and rear)
Check for correct play in the brake levers,
and make sure they are working properl y.
Check brake operation at a very low speed
shortly after starting out.
__ _ ____ ____, -,,. \
- - - - -- - ---./ PLAY
__L
-

Brake lever free play:
10 ,...., 20 mm (0. 4,...., 0.8 in)
Throttle
Turn the throttle grip to see if it operates
properly and whether the play is normal.
Make certain the throttle snaps closed when
re leased.
- 17-
Lights/Signals
Che ck the headlight. tail/stoplight. turn sig-
nal li ghts and all the indicator lights to make
su re they are in working condition.

Tires
Check both front and rear tire pressures. Also
check for nails, fractions of glass, or stones
embedded in tire treads. Check the run-out
of
each tire rim, and recondition, as necessary.
Ask your Yamaha dealer or other qualified
service establishment. if required.
- 18-

WARNING:-----------.
Improper tire pressures greatly affect
tire life and handling . Check tire pres-
sur es prior to each trip and adjust prop-
erly, if necessary.
• If tire pressures are too high , shocks
from the road will not be damped and
will be carried to the frame and
handlebars,thus adverse ly affecting
r iding comfort. In addition, machine
stability will be poor when making a
turn .
• If tire pressures are too low, tires will
be deformed greatly , thus shortening
tire life . When braking the wheels,
tires could slip over wheel rims and
tire tubes could broken . When turning
the corner or the curve, the bi ke could
easily turn over .
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