engine YAMAHA SUPERJET 2003 Service Manual

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CAUTION:@ Do not run the engine at full throttle or
for more than 15 seconds on land, other-
wise the engine may overheat and seize.
@
7. If the watercraft will be stored for a week
or more, lubricate internal engine com-
ponents to help prevent corrosion. (See
page 4-3 for lubrication procedures.)
8. Rinse the engine and engine compart-
ment with a small amount of water.
CAUTION:@ Do not use high pressure when rinsing
the engine or engine compartment as
severe damage could result.
@
9. Wipe the engine and engine compart-
ment dry with a clean cloth (repeat
step 3, if necessary).
10. Wipe the hull, steering pole, handlebars,
and jet unit dry with a clean cloth.
11. Spray a rust inhibitor on metallic parts to
minimize corrosion.
12. Allow the engine compartment to air dry
completely before reinstalling the hood.
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EJU01956
Transporting
WARNING@ Always place the fuel cock knob in the
“OFF” position when transporting the
watercraft, otherwise fuel could leak out
into the engine or engine compartment,
which would create a fire hazard.
@
Transport this watercraft using the special
trailer that incorporates a hole into which the
pin 1 can be inserted and locked after
passing it through the rope hole 2.
After securing the bow with the pin,
secure the stern with ropes or tie downs 4
over the gunwale. Use a rubber shock
cord3 to hold the steering pole.
CAUTION:@
Do not route ropes or tie downs over
the steering pole, as they may damage
it. Also, wrap the ropes or tie downs
with towels or rags where they touch
the body of the watercraft to avoid
scratching or damage.

Do not transport the watercraft with
steering pole up, or the steering pole
may be damaged during transporta-
tion.
@
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EJU01087
Storage
WARNING@ Always place the fuel cock knob in the
“OFF” position when storing the water-
craft, otherwise fuel could leak out into
the engine or engine compartment,
which would create a fire hazard.
@
Storage for prolonged periods of time,
such as winter storage, requires preventa-
tive maintenance to ensure against deterio-
ration. It is advisable to have the watercraft
serviced by a Yamaha dealer prior to stor-
age. However, the following procedures can
be performed by the owner.
EJU01088
Flushing the cooling system
Flushing the cooling system is essential
to prevent the cooling system from being
clogged with salt, sand, or dirt.
CAUTION:@
Do not supply water to the cooling
water passages when the engine is not
running. The water could flow back
through the muffler into the crankcase
causing severe engine damage.

Do not run the engine for more 15 sec-
onds without supplying water, other-
wise the engine may overheat.
@
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1. Put the watercraft on land in a horizontal
position.
2. Open the flushing hose connector cap
1, and then insert the garden hose
adapter 2 into the flushing hose con-
nector 3 and turn it until it is securely
connected.
3. Connect the garden hose adapter to a
water tap using a hose.
4. Start the engine, and then immediately
turn the water supply on until water flows
out continually from the cooling water
pilot outlet.
5. Run the engine at idling speed for about
3 minutes watching the engine condition.
If the engine stops while flushing, turn
the water supply off immediately and
repeat the above steps.
6. Turn the water supply off, and then force
the remaining water out from the cooling
passages by alternately squeezing, and
releasing the throttle lever for 10 to
15 seconds.
7. Stop the engine.
8. Remove the garden hose adapter and
secure the cap.
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EJU01299
Lubrication
WARNING@ To reduce the risk of fire or explosion:
Never pour or spray gasoline, or any sub-
stance other than a rust inhibitor through
the hole in the carburetor silencer cover.
@
CAUTION:@
Make sure to replace the cap securely
after fogging the engine, otherwise
water could enter the engine and
cause damage.

Do not attempt to run the engine at full
throttle or for more than 15 seconds
while the watercraft is out of the water,
otherwise the engine may overheat
and/or seize.
@
1. Open the silencer cap 1 on the silencer.
2. Start the engine with the watercraft in a
well-ventilated area.
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3. With the engine running at a fast idle,
quickly spray as much rust inhibitor as
possible through the hole in the silencer
cover. Keep spraying until the engine
stalls (or a maximum of 15 seconds).
4. Install the cap securely.
5. Lubricate all cables such as the throttle,
choke, and steering cables.
NOTE:@ Use a suitable marine grease applicator to
pressure lubricate the cables and purge out
any moisture between the inner and outer
cables.
@
6. Lubricate the areas of the watercraft
specified under Lubrication points on
page 4-14.
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EJU01090
Fuel system
Draining the fuel system prevents buildup
of varnishes and other harmful deposits that
result when gasoline sits for a prolonged
period of time.
WARNING@ Gasoline is highly flammable and explo-
sive. A fire or explosion can cause
severe injury or death. Shut the engine
off. Drain in well-ventilated areas away
from flames or sparks. Do not smoke.
Avoid spilling gasoline. Wipe up spilled
gasoline immediately.
@
To drain the fuel system:
1. Place the fuel cock knob in the “OFF”
position.
2. Drain the fuel tank using a siphon.
EJU01840
Battery
If the watercraft will not be used for more
than a month, disconnect the negative (–)
lead first, then the positive (+) lead and
breather hose, and then remove the battery
from the watercraft.
Clean the battery casing using fresh
water.
If the battery terminals are dirty or cor-
roded, clean them with a wire brush.
Fully charge the battery, and then store it
in a cool, dark place.
Apply Yamaha marine grease or Yamaha
grease A to the battery terminals.
Check the battery at least every 2 months
and fully charge it if necessary.
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CAUTION:@ The battery may not be usable again if
you store it for a long period without
charging it. Charge the battery periodi-
cally.
@
NOTE:@ The condition of the battery can be known
by checking the specific gravity of the elec-
trolyte. However, you can also know the con-
dition of the battery by measuring the
voltage at both battery terminals. Charge the
battery if the voltage is less than 12 volts.
It is recommended to have a Yamaha dealer
check the specific gravity and to charge the
battery. If you maintain the battery yourself,
be sure to read and follow the instructions
provided with the battery tester and charger
you use.
@
EJU01300
Cleaning the watercraft
Clean the watercraft before storing it for a
long period.
1. Wash down the hull, handlebars, and
drive unit with fresh water.
2. Rinse the engine and bilge area with
fresh water. Drain off all water and wipe
up remaining moisture with clean, dry
rags.
3. Spray the engine’s exterior with a rust
inhibitor and lubricant.
4. Wax the hull with a non-abrasive wax.
5. Wipe all vinyl and rubber components,
such as the engine compartment seals,
with a vinyl protectant.
6. Do not use protectant on the riding tray,
because it will make it slippery. Specific gravity (for reference):
1.28 at 20 °C (68 °F)
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EJU01094
Maintenance and
adjustments
Periodic inspection, adjustment and lubri-
cation will keep your watercraft in the safest
and most efficient condition possible. Safety
is an obligation of the watercraft owner. The
most important points of watercraft inspec-
tion, adjustment and lubrication are
explained on the following pages.
See your Yamaha dealer for genuine
Yamaha replacement parts and optional
accessories designed for your watercraft.
Remember that failures that are the result
of the installation of parts or accessories
which are not qualitatively equivalent to gen-
uine Yamaha parts are not covered by the
limited warranty.
WARNING@
Be sure to turn off the engine when
you perform maintenance unless oth-
erwise specified, otherwise an acci-
dent or injury could result from
unexpected operation, moving parts,
or electric shock. If the owner is not
familiar with watercraft servicing, this
work should be done by a Yamaha
dealer. Improperly serviced compo-
nents could fail or stop operating cor-
rectly, which could result in an
accident.

Modifications to this watercraft not
approved by Yamaha may cause loss
of performance or excessive noise, or
render it unsafe for use. Consult a
Yamaha dealer before attempting any
changes.
@
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EJU01355
Periodic maintenance chart
The following chart gives general guidelines for periodic maintenance. However, depend-
ing on your operating conditions maintenance may need to be performed more frequently.
*1: Grease capacity: 20.0–22.0 cm3 (0.68–0.74 oz)
*2: Grease capacity: 3.0–5.0 cm3 (0.10–0.17 oz)
*3: After every use
*4: Before every use
*5: Inspect fluid level before every use
(
) This mark indicates maintenance that you may do yourself.
(
❍) This mark indicates work to be done by a Yamaha dealer.
MAINTENANCE INTERVAL INITIALTHEREAF-
TER EVERYPA G E
10
hours50
hours100
hours 100
hours 200
hours
ITEM
6
months12
months12
months24
months
Spark plug Inspect, clean, adjust




4-13
Lubrication points Lubricate


4-14
Intermediate housing Lubricate❍
*1

*2

*2 4-16
Fuel system Inspect❍❍
4-10
Fuel filter Check, clean, replace❍❍
4-11
Fuel tank Clean❍
4-11
Carburetor setting Inspect, adjust❍❍❍
4-19
Trolling speed Inspect, adjust


4-19
Carburetor throttle shaft Inspect❍❍
—
Cooling water passages Flush

*34-1
Bilge strainer Clean


—
Impeller Inspect

*4❍❍
—
Jet thrust nozzle angle Inspect


4-12
Steering pivot Inspect❍❍❍
—
Steering friction Inspect, adjust



4-20
Throttle lever Check operation

*44-12
Throttle cable Inspect, adjust


4-12
Choke knob Check operation

*44-16
Choke cable Inspect, adjust ❍❍
4-16
Battery Inspect

*5❍❍
4-17
Rubber coupling Inspect❍
—
Engine mount Inspect❍
—
Nuts and bolts Inspect❍❍❍
—
UF1N71.book Page 9 Tuesday, June 4, 2002 3:34 PM