YAMAHA SUPERJET 2003 Service Manual

3-8
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EJU01054
Battery
Check the battery condition and the elec-
trolyte level.
Check that the battery leads are tightened
securely and there is no corrosion on the
battery terminals.
WARNING@ The battery must always be fully charged
and in good condition. Loss of battery
power may leave you stranded. Never
operate the watercraft if the battery does
not have sufficient power to start the
engine or if it shows any other signs of
decreased power.
@
Make sure that the breather hose is prop-
erly connected and that it is not damaged or
obstructed.
Make sure that the battery is securely
held in place.
1
Positive (+): Red lead
2
Negative (–): Black lead
3
Breather hose
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3-9
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EJU01282
Fire extinguisher
Check that there is a full fire extinguisher
on board. The fire extinguisher container 1
is on the hood under the steering pole.
To open the fire extinguisher container:
1. Grasp the tab 2, pull the band to the
rear, and then pull up.
2. Lift the container about 30 degrees from
the stored position.
3. Remove the cap to reach the fire extin-
guisher.
CAUTION:@ Do not force the fire extinguisher con-
tainer up more than 30 degrees from the
storage position, otherwise the container
or hood could be damaged.
@
To close the fire extinguisher container:
1. Reinstall the cap and tighten it securely
after inserting the fire extinguisher into
the container.
2. Reinstall the container on the hood and
secure it with the band.
NOTE:@
See the instructions supplied by the fire
extinguisher manufacturer for checking
the fire extinguisher. Always keep the
extinguisher in the fire extinguisher con-
tainer.

Always carry a fire extinguisher on board.
A fire extinguisher is not standard equip-
ment with this watercraft. If you do not
have one, contact a Yamaha dealer or a
fire extinguisher dealer to obtain one
meeting the proper specifications.
@
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3-10
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EJU01834
Throttle
Squeeze and release the throttle lever
several times to make sure that there is no
hesitation in its travel. It should be smooth
over the complete range, and spring back to
the idle position when released.
WARNING@ Before starting the engine, always check
the operation of the throttle lever.
@
EJU01057
Steering system
Check for looseness in the handlebars.
Turn them as far as possible to the right
and left to make sure that operation is
smooth and unrestricted throughout the
whole range. Make sure that the jet thrust
nozzle also changes directions as the han-
dlebars are turned, and that there is no free
play between the handlebars and the jet
thrust nozzle.
EJU01281
Steering pole
Check for looseness in the steering pole.
Move it up and down to make sure operation
is smooth and unrestricted throughout the
whole range. Make sure the steering pole
does not have any side play.
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3-11
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EJU01058
Jet unit
Carefully check the jet intake for weeds,
debris, or anything else that might restrict
the intake of water. If the intake is clogged,
cavitation could occur, reducing jet thrust,
and possibly damaging the jet pump.
In some cases, the engine may overheat
because of lack of cooling water, and dam-
age to the engine could result. Engine cool-
ing water is fed to the engine by the jet
pump. (See page 5-3 for jet intake cleaning
procedures.)
WARNING@
Keep away from intake grate while
engine is on. Items such as long hair,
loose clothing, or PFD straps can
become entangled in moving parts
resulting in severe injury or drowning.

Stop the engine and remove the clip
from the engine shut-off switch before
removing any debris or weeds, which
may have collected around the jet
intake.
@
EJU01059
Engine shut-off cord (lanyard)
Check that the engine shut-off cord is not
frayed or broken. If the cord is damaged,
replace it; never try to repair it or tie it
together.
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3-12
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EJU01835
Switches
Check the start switch 1, the engine stop
switch 2, and the engine shut-off switch 3
for proper operation.
To check these switches, place the water-
craft in the water to provide adequate cool-
ing. Start the engine, and then pull the
engine shut-off cord 5 to remove the clip 4
from the engine shut-off switch. Verify that
the engine stops immediately. (See pages
2-5 to 2-6 for information on proper opera-
tion of the start switch, the engine stop
switch and the engine shut-off switch.)
EJU01320
Cooling water pilot outlet
Check that water comes out from the out-
let while the engine is running and the
watercraft is in the water.
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3-13
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EJU01283
Operation
WARNING@ Before operating your watercraft,
become familiar with all controls. Con-
sult your Yamaha dealer about any con-
trols or functions you do not fully
understand. Failure to understand how
controls work could cause an accident or
prevent you from avoiding an accident.
@
EJU01284
Engine break-in
The engine break-in period is essential to
allow the various components of the engine
to wear and polish themselves to the correct
operating clearances. This ensures proper
performance and promotes longer compo-
nent life.
CAUTION:@
For the first 5 hours or 2 tankfuls of
operation, premix fuel and oil in a 25:1
ratio.

After break-in, premix fuel and oil in a
50:1 ratio for normal operation.
@
1. Launch the watercraft and start the
engine, and then board the watercraft.
2. Run the engine at the lowest possible
speed for 5 minutes.
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3. Gradually open the throttle lever to 3/4 or
less.
4. Continue operation at 3/4 throttle or less
until the first tankful of fuel has been
used.
5. Fill the tank once more with a fuel-to-oil
ratio of 25:1, and proceed with normal
operation.
CAUTION:@ Failure to follow the engine break-in pro-
cedure properly can result in severe
damage to the engine.
@
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EJU01137
Starting the engine
WARNING@ Never start the engine or let it run for any
length of time in an enclosed area.
Exhaust fumes contain carbon monox-
ide, a colorless, odorless gas that may
cause loss of consciousness and death
within a short time. Always operate the
watercraft in an open area.
@
1. Launch the watercraft in water free from
weeds and debris and at least 60 cm
(2 ft) deep.
WARNING@ Never operate in water that is less than
60 cm (2 ft) deep, otherwise you increase
your chance of hitting a submerged
object, which could result in injury.
@
CAUTION:@ Never operate in water that is less than
60 cm (2 ft) deep, otherwise pebbles or
sand could be sucked into the jet intake,
causing impeller damage or engine over-
heating.
@
2. Turn the fuel cock knob to the “ON” posi-
tion.
NOTE:@ Before starting the watercraft, after it has
been sitting, remove the fuel tank filler cap
to release any built-up pressure in the tank
due to fuel expansion.
@
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3. Attach the clip 1 to the engine shut-off
switch 2. Also, attach the engine
shut-off cord 3 to your left wrist.
WARNING@ Check that the engine shut-off cord is not
frayed or broken, and keep it free from
the handlebars so the engine stops if the
operator falls off. The engine shut-off
cord may not pull free if wrapped around
the handlebars when the operator falls
off, allowing the watercraft to continue to
run and cause an accident.
@
NOTE:@ It is not possible to start the engine with the
clip removed from the engine shut-off
switch.
@
4. Pull and hold the choke knob all the way
out to start a cold engine.
NOTE:@ The choke should not be used when the
engine is warm.
@
5. While lightly squeezing the throttle lever,
push the start switch (green button).
WARNING@ On this watercraft, the engine is con-
nected directly to the jet pump. Starting
the engine immediately generates some
thrust. Apply only enough throttle to
keep the engine running.
@
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3-17
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6. Release the start switch as soon as the
engine starts to run.
CAUTION:@
Never push the start switch while the
engine is running.

Do not operate the start switch for
more than 5 seconds, otherwise the
battery will be discharged and the
engine will not start. Also, the starter
motor may be damaged. If the engine
does not start in 5 seconds, release
the start switch, wait 15 seconds, and
try again.
@
7. After the engine has warmed up, push
the choke knob in to its original position.
NOTE:@ If the choke knob is left pulled out, the
engine will stall.
@
UF1N71.book Page 17 Tuesday, June 4, 2002 3:34 PM