Yamaha YTZ250S 1986 User manual

INDEX
GENERAL INFORMATION
REGULAR MAINTENANCE
AND ADJUSTMENTS
ENGINE MAINTENANCE AND
REPAIR
CHASSIS MAINTENANCE
AND REPAIR
ELECTRICAL
TROUBLESHOOTING
APPENDICES

D GENERAL INFORMATION
MACHINE IDENTIFiCATION .................................... 1-1
Vehicle Identification Number ................................ 1-1
Engine Serial Number .................................... '" .1-1
CONTROL FUNCTIONS ........................... . ............. 1-2
FUEL,
OIL AND COOLANT ..................................... 1-4
Fuel
......................................................... 1-4
Engine Mixing Oil ............................................ 1-4
Transmission Oil ............................... . ............. 1-4
Coolant Level ................................................ 1-5
Coolant Draining ............................................. 1-5
Replenishing Coolant ......................................... 1-6
SAFETY
INFORMATION ............. . ......................... 1-6
Ride
with Care and Good Judgement ........................ 1-6
Wear Protective Clothing .................................... 1-7
Be Careful where You Ride .................................. 1-8
Modification ................................................. 1-8
RIDING YOUR TRI-MOTO ..................................... 1-9
Getting to Know Your Tri-Moto .............................. 1-9
Learning to Ride Your Tri-Moto .............................. 1-9
Turning Your Tri-Moto ....................................... 1-10
Climbing Uphill .............................................. 1-11
Riding Downhill ............................................. 1-12
Crossing a Slope ........... . ..................... . _ ......... 1-12
Crossing through Shallow Water ............................. 1-13
Riding over Rough Terrain ................................... 1-13
Sliding and Skidding .................................... . .... 1-13
What to Do If ............................................... 1-14
PREOPERATION CHECKS
...................................... 1-15
STARTING AND BREAK-IN .................................... 1-16
Starting a Cold Engine ....................................... 1-16
Starting a Warm Engine ...................................... 1-16
Break-in Procedures .......................................... 1-16
CLEANING AND STORAGE ....................... . ............ 1-17
Cleaning ..................................................... 1-17
Storage ...................................................... 1-18

D GENERAL
INFORMATION
MACHINE IDENTIFICATION
There are two significant reasons for knowing
the serial number
of your machine:
1. When ordering parts, you can give the
number
to your Yamaha dealer for
positive identification
of the model you
own;
2. If your machine is stolen, the authorities
will
need the number to search for and
identify your machine.
Vehicle Identification Number
Engine Serial Number
The engine serial number is stamped into the
elevated part
of the right rear section of the
engine.
The vehicle identification number is stamped ~ .. .. . .. .
on the right of the steering head pipe. II
1. Engine serial number
1. Vehicle identification number
1-1

Shift pedal
N. Neutral
CONTROL FUNCTIONS
CD Engine stop switch
~ Light/Dimmer switch
1-2
Fuel tank cap
1. Marks
NOTE:
The design and specification of the machine
you have purchased may partly differ from
those shown in the photos this manual carries.
Align cap and lever marks correctly.
If misaligned, press again.

CD position: Cold engine start-ambient temp.
above 25°C
(SOOF) and warm
engine start position.
~ position: Cold engine start-ambient temp.
at
O°C (30°F) -30°C (gOOF) and
warming up position.
,
@ position: Cold engine start-ambient temp.
below 5°C (40°F).
Main fuel cock
OFF: With the lever in this position fuel will
not flow. Always return the lever
to this
position when the engine
is not
running.
ON: With the lever in this position fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
----++HI-+-OFF
1-3
Starter knob
0° 10 ° 20 ° 30
0O
C
: : : : )
Q) . 30°
50 ° 70° 90° of
CD
•••• :1
~ {
.. . ....
• ,··········2
.!o:·:';·.i
Reserve fuel cock
RES: This indicates "RESERVE". If you run
out of fuel while riding, move the lever
to this position. THEN, FILL THE TANK
AT THE FIRST OPPORTUNITY. After
refuelling, the fuel cock lever should
be
at "ON".

FUEL, OIL AND COOLANT
Fuel
Recommended fuel:
Premium fuel
with an octane rating of
at least 90.
Fuel tank capacity:
10.0 L (2.2 Imp gal, 2.6 US gal)
Engine Mixing Oil
Recommended oil: Yamalube "R"
(Yamalube Racing 2-cycle oil)
Mixing ratio:
24: 1
If
for any reason you should use another type,
select from the following list.
Recommended oil Mixing ratio (Break-in)
Castrol
R30
A545*
20: 1
A747
*In Germany brand name is Castrol T.T.S., but same quality as
A545.
Never mix two types of oil in the same
batch; clotting of the oil could result.
Transmission Oil
Recommended oil:
SAE 10W30
SE
Transmission oil capacity:
Periodic oil change:
1000 cm3 (0.88 Imp qt, 1.06 US qt)
Overhaul:
1050 cm3 (0.92 Imp qt, 11.0 US qt)
1-4
1. Drain plug
1. Filler plug
CHECKING OIL LEVEL
On the right side of the engine there is a
checking screw. To check, warm up the
engine for 1 minute. Stop engine.
Leave the
engine
as it is for a few minutes and place the
machine upright, then remove the oil level
checking screw. If oil flows out, the oil level is
correct.
1. Checking screw

Coolant Level
WARNING:
Do not remove the radiator cap, drain
bolts and hoses when the engine and
radiator are hot. Scalding hot fluid and
steam may be blown out under pressure,
which could cause serious injury. When
the engine has cooled, place a thick towel
over the radiator cap, slowly rotate the
cap counterclockwise to the detent. This
procedure allows any residual pressure to
escape. When the hissing sound has stop-
ped, press down on the cap while turning
counterclockwise and remove it.
1. Remove the right side cover.
2. Check the coolant level in the radiator
tank when the engine is cold. If the
coolant level is low, add the coolant.
1. Radiator cap
1-5
1. Coolant level
2. To recovery tank
3. Check the coolant level in the recovery
tank when the engine is cold.
If the coolant level is below the "LOW"
level add the coolant upto "FULL" level.
Recommended coolant:
High quality ethylene glycol antifreeze
containing corrosion inhibitors for
aluminum engine
Coolant capacity:
1.0 L (0.88 Imp qt, 1.057 US qt)
Coolant and water mixed ratio:
1 : 1 (50% water, 50% coolant)
Do not mix more than one type of
ethylene glycol antifreeze containing cor-
rosion
for aluminum engine inhibitors.
Hard water or salt water is harmful to the
engine parts. You may use distilled water,
if you can't get soft water.

Coolant Draining
1. Place a container under the engine.
2. Remove the radiator tank cap.
3. Gently loosen the pump cover drain
screw
to drain the coolant, and remove
the cylinder drain bolt. ,
,. Pump cover drain bolt
2. Cylinder drain bolt
4. Drain the coolant completely. Thoroughly
flush the cooling system
with clean tap
water.
Take care so
that coolant does not splash
on painted surfaces. If it splashes, wash it
away with water.
5. Retighten the drain bolts.
If the gasket is damaged, replace it.
Replenis . hing Coolant
NOTE: ______________________ _
Before pouring the coolant into the radiator,
check the cooling system
for damage, loose
joints or leaks.
1. Pour the recommended coolant into the
radiator up
to the specified level.
2. After starting the engine, race the engine
a few times and add the coolant again up
to the specified level.
3. When the coolant level becomes stable,
stop the engine and tighten the radiator
cap.
1-6
SAFETY INFORMATION
When you ride your machine, you must know
and use the following for your safety:
Ride
with Care and Good Judgement:
1. Speed limiter
For beginning riders, this model
is equip-
ped
with a speed limiter in the throttle
lever housing. The speed limiter limits the
top speed
of the machine. Turning the
screw
in decreases the top speed and tur-
nningit out increases the top speed. (See
(page 2-8)
2. Riding your machine requires skills ac-
quired through practice over a period
of
time. Take the time to learn the basic
techniques well before attempting more
difficult maneuvers.
3. This machine
is designed to carry one per-
son only. Do
not carry a passenger.

ONE PERSON
ONLY
4. Always perform the Pre-Operation Checks
on page 1-15 before riding for safety and
proper care
of the machine.
5. The exhaust system on the machine
is
very hot during and following operation.
To prevent burns, avoid touching the ex-
haust system.
Park the machine in a place
where pedestrians or children
are not likely
to touch it.
6. Always keep your feet on the footrests
during operation. Otherwise your feet may
contact the rear wheels.
1-7
7. Avoid wheelis and jumping. You may lose
control
of the machine or overturn.
8. Use extra caution when riding the
machine with additional loads, such
as ac-
cessories, cargo, or a trailer. The
machine's handling may
be adversaly af-
fected. Reduce your speed when adding
additional loads.
9. When transporting the machine in
another vehicle,
be sure it is kept upright
and that the fuel cock
is turned to the
"OFF" position. If the machine should
lean over, gasoline may leak out
of the
carburetor
of fuel tank.
Wear Protective Clothing:
1. ALWAYS wear a helmet when riding your
machine. Goggles or other
eye protection
should also
be worn.
2. Wear boots, gloves, long pants and other
protective clothing.

1. Helmet
3. Long pants
5. Gloves
2. Protective clothing
4. Boots
6. Goggles
Be Careful where You Ride:
1. This machine is designed for off-road use
only. Riding on pavement is not recom-
mended since handling can be seriously
affected.
If you must ride on paved sur-
faces, go slowly and do not make sudden
turns or stops. Riding on pavement will
also shorten tire life.
2. Ride cautiously in unfamiliar areas. You
may encounter hidden obstacles which
could cause
an accident.
3. Do not ride
in areas posted "no trespass-
ing. " Do not ride on private propertly
without getting permission.
4. When riding in an area where you might
not easily
be seen, such as desert terrain,
mount a caution flag on the machine. Do
NOT
use the flag pole bracket as a trailer
hitch.
Modifications:
1. This machine is designed to conform with
laws and regulations regarding spark ar-
resters and noise level. Do not modify the
exhaust system.
2. Modifications to this machine may reduce
safety and reliability, and may make the
machine illegal for use.

RIDING YOUR TRI-MOTO
Getting to Know Your Tri-Moto
Riding your Tri-Moto requires skills ac-
quired through practice over a period of
time. Take the time to learn the basic
techniques well before attempting more
difficult maneuvers.
Riding your new Tri-Moto can be a very en-
joyable activity, providing your
with hours of
pleasure. But it is essential to familiarize
yourself
with the operation of the Tri-Moto to
acheive the skill necessary to enjoy riding safe-
ly. Before you begin
to ride be sure you have
read this Owner's Manual and Service com-
pletely and understand the operation
of the
controls.
Pay particular attention to the safety
information on page
1-6 - 1-8. Please also read
all caution and warning labels on your
Tri-Moto.
Remember: your Tri-Moto
is designed for one
person operation only. Do not carry passe-
ngers.
Learning to Ride Your Tri-Moto
Before you ride always perform the
Preoperation Checks on page 1-15. The
short time spent checking the condition
of the machine will be rewarded with add-
ed safety and a more reliable Tri-Moto.
Always wear a helmet and goggles or other eye
protection when you ride. You should also
wear gloves, boots, long pants and other pro-
tective clothing while riding your Tri-Moto.
Keep your hands on the handlebers and your
feet on the footrests
for safety and control.
WARNING:
Be sure to keep your feet on the footrests
at all times while riding. Otherwise, your
feet may come in contact with the rear
wheels and may possibly suffer injury.
1-9
Select a large, flat area off-road to become
familiar with your Tri-Moto. Make sure that this
area is free of obstacles and other riders. You
should practice control
of the throttle, brakes,
shifting procedures, and turning techniques
in
this area before trying more difficult terrai n.
Avoid riding on paved surfaces: the Tri- Moto
is designed for off-road use only, and handl-
ing maneuvers
are more difficult to perform on
pavement.
Always
put the machine into neutral gear to
start the engine. Once it has warmed up you
are ready to begin riding your Tri-Moto. As you
get on the Tri-Moto,
be sure not to acciden-
tally move the change pedal. Remember that
the engine and exhaust pipe will
be hot when
riding and afterwards; do not allow skin or
clothing
to come in contact with these
components.
Apply clutch lever, shift down the change pedal
to the 1st gear position and then release the
.clutch lever. Apply the throttle slowly and
smoothly. Once the Tri-Moto
has attained ade-
quate speed, release the throttle and apply
clutch lever,
lift the change pedal to the 2nd
gear position.
Release the clutch lever and app-
ly the throttle smoothly.
Use this same pro-
cedure
as you move into the higher gears. Be
sure to coordinate the use of the throttle, clutch
lever, and change pedal properly.
Avoid
higher speeds until you are thoroughly
familiar with the operation of your
Tri-Moto.
Do not shift gears without applying clutch
lever. Damage to the engine or drive train
may occur.
WARNING:
Avoid lifting the front wheel off the
ground or making the machine "wheelie."
Loss of directional control, overturning, or
an accident may occur.

When slowing down or stopping, release the
throttle and apply the brakes smoothly and
evenly.
As you slow down, shift to a lower
gear.
Be sure that the engine has sufficiently
slowed before engaging a lower gear. Improper
use of the brakes orshifting can cause the tires
to lose traction, reducing control and increas-
ing the possibility
of an accident.
42
WARNING:
Do not engage a lower gear when the
engine speed is too high. This may cause
the wheels to stop rotating which could
lead to possible engine and drive train
damage, loss of control, and injury.
Turning Your Tri-Moto
Having 3 wheels, the Tri-Moto requires a tur-
ning technique different from that you would
use for a2 or 4 wheel vehicle. To achieve max-
imum traction while riding off-road, the
two
rear wheels are mounted solidly on one axle
and
turn together at the same speed.
Therefore, unless the wheel on the inside
of
the turn is allowed to slip or lose some trac-
tion, the
Tri-Moto will resist turning. A
special turning technique must
be used to allow
the
Tri-Moto to make turns quickly and easily.
It is essential that the skill be learned first at
low speed.
1-10
As you approach acurve, slow down and begin
to turn the handlebars in the desired direction.
As you do so, put your
weight on the foot peg
to the outside of the turn (opposite your desired
direction) and lean your upper body into the
turn.
Use the throttle to maintain an even spped
through the turn. This maneuver will let the
wheel on the inside
of the turn slip slightly,
allowing the
Tri-Moto to make the turn
properlY·
..
Lean towards
inside of turn.
This procedure should be practiced at slow
spped many times in a large off -road area with
no obstacles. If an incorrect technique is us-
ed, your Tri-Moto may continue
to go straight.
If the
Tri-Moto doesn't turn, come to a stop
and then practice the procedure again.
If the
riding surface
is slippery or loose, it may help
to position more of your weight over the front
wheel by moving forward on the seat. Once
you have learned this technique you should be
able
to perform it at higher speeds or in tighter
curves.
Improper riding procedures such
as abrupt
throttle changes, excessive braking, incorrect
body movements, or
too much speed for the
sharpness
of the turn may cause the Tri-Moto
to tip. If the Tri-Moto begins to tip over to the
outside whiile negotiating aturn, lean more
to
the inside. It may also be necessary to gradual-
ly let off on the throttle and steer to the out-
side
of the turn to avoid tipping over.
When riding your Tri-Moto around a curve,
remember
that the rear wheels are placed fur-
ther out
to the sides than the front one. Be sure
that the rear wheels will also clear obstacles.

Remember: Avoid higher speeds until you
are thoroughly familiar with the operation
of your Tri-Moto.
Climbing Uphill
Be sure that you can maneuver your Tri-Moto
well on flat ground before attempting any in-
cline and then practice riding first on gentle
slopes. Try more difficult climbs only after you
have developed you skill.
In all cases avoid in-
clines
with slippery or loose surfaces, or
obstacles that might cause you
to lose control.
It
is important when climbing a hill to make sure
that your weight is transferred forward on the
Tri-Moto. This can be accomplished by lean-
ing forward and, on steeper inclines, standing
on the footrests and leaning forward over the
handlebars.
Be sure that you are using asteady speed when
you climb a hill, not so fast that you can lose
control or so slow that the engine will stall.
Downshift quickly and smoothly,
if necessary,
to maintain sufficient engine power.
WARNING:
Avoid sudden bursts of throttle which
could cause the machine to "wheelie"
when climbing a hill. The front wheel must
be kept on the ground to avoid loss of
directional control and to prevent the
possibility of the Tri-Moto tipping over
backwards.
1-11
If you are climbing a hiil and you find that you
have
not properly judged your ability to make
it to the top, you should turn the Tri-Moto
around while you still have forward motion
(provided you have the room
to do so) and go
down the hill.
WARNING:
DO NOT attempt turning around on a hill
unless you have mastered the turning
technique on flat ground.
If your Tri-Moto has stalled or stopped and you
believe you can continue up the hill, restart
carefully
to make sure you do not lift the front
wheel which could cause you to lose control.
If you
are unable to continue up the hill, dis-
mount the Tri-Moto on the
uphill side.
Physically turn the Tri-Moto around and then
descend the hill.
Ifyou start
to roll backwards, DO NOT use the
rear brake
to stop or try to put the Tri-Moto
in gear. The Tri-Moto could easily tip over
backwards. Instead, dismount the Tri-Moto im-
mediately on the
uphill side.
WARNING:
When dismounting your Tri-Moto on a
slope, always dismount and stay on the
uphill side to avoid the possibility of the
Tri-Moto rolling over on top of you.
Do not use the rear brake to try to stop the
Tri-Moto if it is rolling backwards down a
hill or attempt to put the Tri-Moto in gear.
The Tri-Moto may tip over on top of
youresulting in injury. Dismount the Tri-
Moto immediately on the uphill side.

Riding Downhill
When riding your Tri-Moto downhill, shift your
weight
as far to the rear and uphill side of the
Tri-Moto
as possible. Move back on the seat
and sit
with your arms straight. Choose a low
gear which will allow the engine compression
to do most of the braking for you. Improper
braking may cause a loss
of traction.
Use caution while descending a hill with a loose
or slippery surface. Braking ability and traction
may
be adversely affected by these surfaces.
Improper braking may also cause a loss
of
traction.
Whenever possible, ride your Tri-
Moto straight
downhi
ll. Avoid sharp angles wh i ch could allow
the Tri-Moto to tip or roll over. Carefully choose
your path and ride on faster than you will
be
able to react to obstacles which may appear.
1-12
Crossing a Slope
Traversing a sloping surface on your Tri-Moto
requires you
to preperly position your weight
to maintain proper balance. Be sure that you
have learned the basic riding skills on flat
ground before attempting
to cross a sloping
surface. Avoid slopes with slippery surfaces or
rough terrain that may upset your balance.
As you travel across a slope, lean your body
in the uphill direction. It may be necessary to
correct the steering when riding on loose sur-
faces by pointing the
front wheel slightly
uphill. When riding on slopes be sure not to
make sharp turns either up or down hill.
Ifyour Tri-Moto does begin to tip over, gradual-
ly steer
in the downhill direction if there are no
obstacles in your path. As you regain proper
balance, gradually steer again in the direction
you wish
to travel.
WARNING:
There is greater danger of tipping when
riding on sloping surfaces. Tipping may
cause loss of control. If you are unable to
maintain correct balance and you discover
that the Tri-Moto is going to tip over, dis-
mount the Tri-Moto immediately on the
uphill side.

Crossing through Shallow Water
The Tri-Moto can be used to cross slow mov-
ing, shallow water of up to a maximum of
30 cm (1.2 inches) in depth. Before entering the
water, choose your path carefully. Enter where
there
is no sharp drop off, and avoid rocks or
other obstacles which may be slippery or upset
the Tri-Moto. Drive slowly and carefully.
Remember that brakes which
are wet may have
reduced stopping ability. Test your brakes after
leaving the water and apply them several times,
if necessary, to let the friction dry out the lin-
ings. Do
not continue to ride your Tri-Moto
without verifying that you have regained pro-
per braking ability.
WARNING:
Do not ride the Tri-Moto into water deeper
than 30 cm (1.2 inches), or fast moving
water. The tires may float causing a loss
of traction, loss of control, and an accid-
ent.
1-13
Riding over Rough Terrain
Riding over rough terrain should be done with
caution. Look out for obstacles which could
cause damage
to the Tri-Moto or could lead
to an upset or accident. Be sure to keep your
feet firmly mounted on the footrests at all
times.
Avoid jumping the Tri-Moto as loss of
control and damage to the Tri-Moto may result.
WARNING:
Use extreme caution when crossing sharp
bumps. Crossing at too great a speed
could cause the Tri-Moto to be upset,
resulting in loss of control with the
possibility of an accident and injury.
Sliding and Skidding
Care should be used when riding on loose or
slippery surfaces since the Tri-Moto may slide.
If unexpected and uncorrected, sliding could
lead
to an accident.
To reduce the tendency
for the front wheel to
slide in loose or slippery conditions, position-
ing your
weight over the front wheel will
sometimes help.
--- ~
---- - ---------- --,- -- -
1
\
If the rear wheels of your Tri-Moto start to slide
sideways, control can usually be regained
(if
there is room to do so) by steering in the direc-
tion
of the slide. Applying the brakes or ac-
celerating
is not recommended until you have
corrected the slide.

With practice, over a period of time, skill at
controlled sliding can
be developed. The ter-
rain should
be chosen carefully before attemp-
ting such maneuvers, since both stability and
control are reduced. Bear
in mind that sliding
maneuvers should always
be avoided on ex-
tremely slippery surfaces such
as ice, since all
control may be lost.
WARNING:
Sliding or skidding on pavement must be
avoided at all times because traction may
be regained without warning, causing the
Tri-Moto to turn over and result in an ac-
cident or injury.
Be careful when braking on loose or slip-
pery surfaces. Improper use of the brakes
can cause uncontrolled sliding, reducing
control and increasing the possibility of an
accident.
What to Do If ...
This section
is designed to be a reference guide
only.
Be sure to read each section on riding
techniques
completely.
WHAT TO DO ...
•
If your Tri-Moto doesn't turn when you
want it to:
Bring the Tri-Moto
to a stop and practice
the turning maneuvers again.
Be sure you
are putting your weight on the footrest to
the outside of the turn. Position your
weight over the
front wheel for better
control.
(see pages 1-10 and 1-11) 1-14
• If your Tri-Moto begins to tip while
turning:
•
Lean more into the turn to regain balance.
If necessary gradually let off on the throt-
tle
and/ or steer to the outside of the turn
(see pages 1-10 and 1-11)
If your Tri-Moto starts to slide sideways:
Steer
in the direction of the slide if you
have the room.
Applying the brakes or accelerating
is not
recommended until you have corrected
the slide.
(see pages 1-13 and 1-14)
• Ifyour Tri-Moto can't make it up a hill you
are trying to climb:
Turn the Tri-Moto around
if you still have
forward speed.
If not, stop dismount on
the uphill side
of the Tri-Moto and
physically turn the Tri-Moto around. If the
Tri-Moto starts
to slip backwards DO NOT
USE THE
REAR BRAKE-the Tri-Moto
may tip over on top
of you. Dismount the
Tri-Moto on the uphill side.
(see pages **,
1-11 and 1-12)
•
If your Tri-Moto is traversing a sloping
surface:
Be sure to ride with your weight position-
ed towards the uphill side of the Tri-Moto
to maintain proper balance. If the Tri-
Moto starts to tip, steer down the hill (if
there are no obstacles in your way) to
regain balance. If you discover that the
Tri-Moto
is going to tip over, dismount on
the uphill side.
(see pages 1-12)
• If your Tri-Moto encounters shallow
water:
Ride slowly and carefully through slow
moving water, watching for obstacles.
Be
sure to let weter drain from the Tri-Moto
and CHECK YOUR BRAKES
FOR PRO-
PER OPERATION when you come out of
the water. Do not continue to ride your
Tri-Moto until you have regained ade-
quate braking ability.
(see pages 1-13)

PREOPERATION CHECKS
Before riding for break-in operation, practice
or a
race, make sure the machine is in good
operating condition.
INSPECTION
AND MAINTENANCE
Cooling water
Check that water is filled up to the radiator
filler cap.
Fuel
Check that a fresh mixture
of oil and gasoline
is filled in the fuel tank.
WARNING:
Do not overfill the fuel tank. Avoid spill-
ing fuel on the hot engine.
Do not fill the fuel tank all the way to the
top
or it may overflow when the fuel heats
up later and expands.
After refueling, make sure the tank cap is
closed securely.
Gear oil
Check that the gear oil level is correct.
Gear
shifter and clutch
Check that gears can be shifted correctly in
order and that the clutch operates smoothly.
Brakes
Check the play of both front and rear brakes
and their braking effect.
Chain
Check chain tension and alignment. Check
that the chain
is lubricated properly.
Wheels
Is the tire pressure correct?
Check for excessive wear.
Steering
Check that the handlebars can be turned
smoothly and have no excessive play.
1-15
Front forks and rear shock
Check that they operate smoothly and there is
no oil leakage.
Cables (Wires)
Check that the clutch, brake and throttle
cables move smoothly. Check that they
are
not caught when the handlebars are turned or
when the
front forks travel up and down.
Muffler
Check that the muffler is tightly mounted and
has no cracks.
Sprocket
Check that the rear wheel sprocket tightening
bolt
is not loose.
Bolts and nuts
Check the chassis and engine for loose bolts
and nuts.
Fuel,
oil and coolant
Check the fuel tank, fuel cock, carburetor,
engine bottom, and
.. cooling system for
leakage.
Lead
wire connectors
Check that the CDI magneto, CDI unit, and ig-
nition coil
are connected tightly.
Settings
Is the machine set suitably for the condition of
the racing course and weather or by taking in-
to account the results
of test-runs before rac-
ing?
Is inspection and maintenance complete-
ly done?
* The machine should be checked and
serviced regularly so that only a simple,
minor adjustment
of settings is required
prior
to a race.

STARTING AND BREAK-IN
Before starting the machine, perform the
checks in the preoperation check list.
WARNING:
• Avoid "wheelies" and jumping to pre-
vent loss of control.
• Always put your feet on the footrests
during operation. If you should take
your feet off the footrests, they may
contact the rear wheels.
• Never start or run the engine in a clos-
ed area.
The exhaust fumes are pois-
onous; they can cause loss of con-
sciousness and death in a very short
time. Always operate the machine in
a well-ventilated area.
Starting a Cold Engine
Shift the transmission into neutral. Turn on
the fuel cock and full open the starter knob on
the carburetor.
With the throttle completely
closed, kickstart the engine with a smooth, firm
stroke. Half-open the starter knob, run the
engine
at idle or slightly higher until it warms
up; this usually takes about one or
two
minutes. The engine is warmed up when it
responds normally to the throttle with the
starter knob pushed completely down.
Do not warm up the engine for extended
periods.
Starting a Warm Engine
Do not raise the starter knob. Open the throt-
tle slightly and kickstart the engine
with a
smooth, firm stroke.
Observe the following break-in pro-
cedures
during initial operation to ensure
optimum performance and avoid engine
damage.
1-16
Break-in Procedures
1. Before starting the engine, fill the fuel
tank with a break-in oil-fuel mixture
of
12: 1 to 14: 1.
2. Perform the preoperation checks on the
machine.
3. Start and warm up the engine. Check the
idle speed, and check the operation
of
the controls and the engine stop switch.
4. Operate the machine in the lower gears
at moderate throttle openings
for five to
eight minutes. Stop and check the spark
plug condition;
it will show a rich condi-
tion during break-in.
5. Allow the engine to cool. Restart the
engine and oeprate the machine
as in the
step above
for five minutes. Then, very
briefly shift
to the higher gears and check
full-throttle response. Stop and check
the spark plug.
6. After again allowing the engine to cool,
restart and run the machine for five more
minutes.
Full throttle and the higher gears may be
used,
but sustained full-throttle opera-
tion should be avoided. Check the spark
plug condition.
7. Allow the engine to cool, remove the top
end, and inspect the piston and cylinder;
instructions
for this are described
Chapter 3 "CYLINDER HEAD". Remove
any high spots on the piston
with
6OO-grit, wet sandpaper. Clean all com-
ponents and carefully reassemble the top
end.
8. Drain the break-in oil-fuel mixture from
the fuel tank and refill
with the specified
mix. Check the entire machine
for loose
screws, bolts, and nuts.
9. Restart the engine and check the opera-
tion
of the machine throughout its entire
operating range. Stop and check the
spark plug , condition. Restart the
machine and operate
it for about 10 to 15
more minutes. The machine will now be
ready
to race.

1. After the break-in period is com-
pleted, check the entire machine for
loose fittings and fasteners. Tighten
all such fasteners as required.
2. When any of the following parts have
been replaced, they must be broken
in.
CYLINDER
AND CRANKSHAFT:
About one hour of break-in operation
is necessary.
PISTON, RINGS, GEARS:
These
parts require about 30 minutes
of break-in operation at half-throttle
or less. Observe the condition of the
engine carefully durin{J operation.
1-17
CLEANING AND STORAGE
Cleaning
Frequent cleaning
of your machine will
enhance its appearance, maintain good overall
performance, and extend the life
of many
components.
1. Before washing the machine, block off
the end of the exhaust pipe to prevent
water from entering. A plastic bag
secured
with a rubber band may be used
for this purpose.
2. If the engine is excessively greasy, apply
some degreaser
to it with a paint brush.
Do not apply degreaser
to the chain,
sprockets, or wheel axles.
3. Rinse the dirt and degreaser off with a
garden hose;
use only enough pressure
to do the job.
Excessive hose pressure
can force water
into wheel bearings, front fork seals, and
transmission seals. Avoid using high-
pressure hoses such as those found in
coin-operate car washes.
4. After the majority of the dirt has been
hosed off, wash all surfaces with warm
water and a mild detergent.
Use an old
toothbrush to clean hard-to-reach
places.
5. Rinse the machine off immediately with
clean water, and dry all surfaces with a
soft towel or cloth.
6. Immediately after washing, remove ex-
cess water from the chain with a paper
towel and lubricate the chain
to prevent
rust.
7. Clean the seat with a vinyl upholstery
cleaner
to keep the cover pliable and
glossy.
8. Automotive wax may be applied to all
painted or chromed surfaces. Avoid
combination cleaner-waxes,
as they may
contain abrasives.
9. After completing the above, start the
engine and allow
it to idle for several
minutes.

Storage
If your machine is to be stored for 60 days or
more, some preventive measures must
be
taken to avoid deterioration. After cleaning
the machine thoroughly, prepare
it for storage
as follows:
1. Drain the fuel tank, fuel lines, and the
carburetor float bowl.
2. Remove the spark plug, pour a table-
spoon
of SAE 10W30 motor oil in the
spark plug hole, and reinstall the plug.
With the engine stop switch pushed in,
kick the engine over several times
to coat
the cylinder walls
with oil.
3. Remove the drive chain, clean it
thoroughly with solvent, and lubricate it.
Reinstall the chain or store
it in a plastic
bag tied
to the frame.
4. Lubricate all control cables.
5. Block the frame up to raise the wheels of
the ground.
6. Tie a plastic bag over the exhaust pipe
outlet
to prevent moisture from entering.
7. If the machine is to be stored in a humid
or salt-air environment, coat
all exposed
metal surfaces
with a film of light oil. Do
not apply oil to rubber parts or the seat
cover.
NOTE: ______________________ __
Make any necessary repairs before the
machine
is stored.
1-18