ECU YAMAHA SUPERJET 2008 User Guide

Maintenance and care
46
EJU33480
Storage
WARNING
EWJ00320
Always turn the fuel cock knob to “OFF”
when storing the watercraft, otherwise
fuel could leak out into the engine or en-
gine compartment, which would create a
fire hazard.
Storage for long periods of time, such as win-
ter storage, requires preventive maintenance
to ensure against deterioration. It is advisable
to have the watercraft serviced by a Yamaha
dealer prior to storage. However, the following
procedures can be performed by the owner.
EJU33512Flushing the cooling system
Flushing the cooling system is essential to
prevent it from clogging with salt, sand, or dirt.
CAUTION:
ECJ00920

Do not supply water to the cooling water
passages when the engine is not run-
ning. The water could flow back through
the muffler into the crankcase, causing
severe engine damage.

Do not run the engine for more than 15
seconds on land without supplying wa-
ter, otherwise the engine could over-
heat.
(1) Place the watercraft in a horizontal posi-
tion.
(2) Remove the flushing hose connector
cap, and then insert the garden hose
adapter into the flushing hose connector
and turn it until it is securely connected.
(3) Connect the garden hose adapter to a
water tap using a garden hose.
NOTE:
A garden hose is not included and must be
purchased separately.
(4) Start the engine, and then immediately
turn the water supply on until water flows
out continually from the cooling water pi-
lot 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 of the cooling
water passages by alternately squeezing
and releasing the throttle lever for 10 to
15 seconds.
(7) Stop the engine.
1Garden hose adapter
2Flushing hose connector
3Flushing hose connector cap
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Maintenance and care
47
(8) Remove the garden hose adapter and in-
stall the flushing hose connector cap.
EJU33561Lubrication
WARNING
EWJ00300
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:
ECJ00151

Be sure to install the silencer cap se-
curely after fogging the engine, other-
wise water could enter the engine and
cause damage.

Do not run the engine for more than 15
seconds without supplying water, other-
wise the engine could overheat.
(1) Remove the silencer cap.
(2) Start the engine with the watercraft in a
well-ventilated area.
(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 silencer 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 ca-
bles.
(6) Lubricate the areas of the watercraft
specified in “Lubrication points” on page
58.
EJU33640Fuel system
WARNING
EWJ00290
GASOLINE AND ITS VAPORS ARE HIGH-
LY FLAMMABLE AND EXPLOSIVE!

Do not smoke when refueling, and keep
away from sparks, flames, and other
sources of ignition.

Stop the engine before refueling.

Refuel in a well-ventilated area with the
watercraft in a horizontal position.

Do not stand or sit on the watercraft
while refueling in case of fire.

Take care not to spill gasoline. If gaso-
line spills, wipe it up immediately with
dry rags. Always properly dispose of
gasoline-soaked rags.

Avoid overfilling the fuel tank. Stop fill-
ing when the fuel level just reaches the
bottom of the filler tube. Do not fill up the
filler tube because fuel expands as it
warms up and could overflow. If tempo-
rarily leaving the watercraft with a full
fuel tank, do not leave it in direct sun-
light. Leave it in a well-ventilated area
with the watercraft in a horizontal posi-
tion.

Tighten the fuel tank filler cap securely
after refueling.

If you should swallow some gasoline, in-
hale a lot of gasoline vapor, or get gaso-
1Silencer cap
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Maintenance and care
57
(4) Hold the adjuster with one wrench while
tightening the locknut with another
wrench.
(5) Install the handlebar cover and the four
screws.
EJU34371Cleaning and adjusting the spark
plugs
WARNING
EWJ00350
Be careful not to damage the insulator
when removing or installing a spark plug.
A damaged insulator could allow sparks to
escape, which could result in a fire or ex-
plosion.
The spark plug is an important engine compo-
nent and is easy to inspect. The condition of
the spark plug can indicate something about
the condition of the engine. For example, if the
center electrode porcelain is very white, this
could indicate an intake air leak or carburetion
problem in that cylinder. Do not attempt to di-
agnose any problems yourself. Have a
Yamaha dealer service the watercraft.
Remove and inspect the spark plugs periodi-
cally; heat and deposits will cause the spark
plugs to slowly break down and erode. If elec-
trode erosion becomes excessive, or if carbon
and other deposits are excessive, replace the
spark plug with the specified plug.Measure the spark plug gap with a wire thick-
ness gauge. Replace the spark plugs or ad-
just the gap to specification if necessary.
To install a spark plug:(1) Clean the gasket surface.
(2) Wipe any dirt from the threads of the
spark plug.
(3) Install the spark plug, and then tighten it
to the specified torque.
(4) Install the spark plug cap.
NOTE:

Wipe off any water on the spark plug or in-
side the spark plug cap before installing the
cap. Push the spark plug cap down until it is
securely installed.

If a torque wrench is not available when you
are installing a spark plug, a good estimate
of the correct torque is 1/4 turn to 1/2 turn
past finger tight using the spark plug
wrench included in the tool kit. Have the
spark plug adjusted to the correct torque
with a torque wrench as soon as possible.
Throttle lever free play:
7.0–10.0 mm (0.28–0.39 in)
Specified spark plug:
BR7HS
1Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Spark plug tightening torque:
25.0 Nm (18.4 ft-lb) (2.55 kgf-m)
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Maintenance and care
58
EJU34400Lubrication points
To keep moving parts sliding or rotating
smoothly, coat them with water-resistant
grease.

Throttle cable (carburetor end)

Choke cable (carburetor end)

Throttle cable (handlebar end)
Squeeze the throttle lever and remove the
seal. Spray a rust inhibitor into the outer ca-
ble. Refit the seal securely.

Steering cable ball joint (handlebar end)

Steering cable inner wire (handlebar end)
(1) To access the steering cable and ball
joint, remove the steering pad by re-
moving the two bolts.(2) Grease the steering cable ball joints,
both at the handlebar end of the cable
and at the jet thrust nozzle end.
(3) Extend the steering cable inner wire,
and then apply a thin coat of grease to
the inner wire, both at the handlebar
end of the cable and at the jet thrust
nozzle end.

Steering cable ball joint (jet thrust nozzle
end)

Steering cable inner wire (jet thrust nozzle
end)

Handlebar pivot shaft
Lubrication of the handlebar pivot shaft re-
quires disassembly of steering compo- Recommended water-resistant grease:
Yamaha Marine Grease/Yamaha
Grease A
1Seal
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Maintenance and care
60
EJU34451Checking the battery
Check the level of the battery electrolyte and
make sure that the negative (–) and positive
(+) battery leads are tightened securely.
WARNING
EWJ00790
Battery electrolyte is poisonous and dan-
gerous, causing severe burns, etc. Elec-
trolyte contains sulfuric acid. Avoid
contact with skin, eyes, or clothing.
Antidotes
External: Flush with water.
Internal: Drink large quantities of water or
milk. Follow with milk of magnesia, beaten
egg, or vegetable oil. Call a physician im-
mediately.
Eyes: Flush with water for 15 minutes and
get prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flames, cigarettes, etc., well away.
If using or charging the battery in an en-
closed space, make sure that it is well ven-
tilated. Always shield your eyes when
working near batteries.
KEEP OUT OF THE REACH OF CHILDREN.
CAUTION:
ECJ00230

Be careful not to place the battery on its
side.

Be sure to remove the battery from the
battery compartment when adding elec-
trolyte or charging the battery.
To remove the battery:
Disconnect the negative (–) battery lead first,
then the positive (+) battery lead and breather
hose, and then remove the battery from the
watercraft.To replenish the battery:
(1) Make sure that the electrolyte level is be-
tween the maximum and minimum level
marks.
(2) If the electrolyte level is low, add distilled
water to raise it to the specified level.
CAUTION:
ECJ00240
Normal tap water contains minerals that
are harmful to a battery. Use only distilled
water for replenishing the battery.
To recharge the battery:
CAUTION:
ECJ00250
Do not attempt to charge a battery hastily.
Battery life could be shortened.
It is recommended to have a Yamaha dealer
charge the battery. If you charge the battery
yourself, be sure to read and follow the in-
structions provided with the battery tester and
charger you use.
To install the battery:
(1) Place the battery in the battery compart-
ment and connect the battery leads to the
battery terminals.
(2) Connect the breather hose to the battery.
1Maximum level mark
2Minimum level mark
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Maintenance and care
61
(3) Secure the battery in place.
WARNING
EWJ00400
Be sure to connect the breather hose to
the battery. Fire or explosion could result
if the breather hose is damaged, obstruct-
ed, or not connected properly.
CAUTION:
ECJ00260
After installation, make sure that the bat-
tery leads are properly connected to the
battery terminals.
EJU34460Adjusting the carburetor
The carburetor is a vital part of the engine and
requires very sophisticated adjustments.
Most adjustments should be left to a Yamaha
dealer who has the professional knowledge
and experience to make them. However, the
operator may adjust the trolling speed as part
of the usual maintenance routine.
CAUTION:
ECJ00170
The carburetor was set at the Yamaha fac-
tory after many tests. If the settings are
disturbed by someone who does not have
the necessary technical knowledge, poorengine performance and damage may re-
sult.
EJU34470Adjusting the trolling speed
(1) Place the watercraft in the water.
(2) Start the engine and warm it up for 1 to 2
minutes.
(3) While using a diagnostic tachometer, turn
the throttle stop screw to adjust the en-
gine speed to specification. Turn the
throttle stop screw clockwise to increase
the engine speed or counterclockwise to
decrease the engine speed.
1Positive (+) battery terminal: Red lead
2Negative (–) battery terminal: Black lead
3Breather hose
1Throttle stop screw
Trolling speed:
1300 ±50 r/min
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Trouble recovery
66
CAUTION:
ECJ00660

Place a suitable clean cloth or carpeting
underneath the watercraft to protect it
from abrasions and scratches.

Always turn the watercraft over onto its
port (left) side.

When turning the watercraft on its side,
support the bow so that the handlebars
are not bent or damaged.
(2) Remove any weeds or debris from
around the drive shaft, impeller, jet pump
housing, and jet thrust nozzle.
If debris is difficult to remove, consult a
Yamaha dealer.
CAUTION:
ECJ00670
Always avoid operating your watercraft in
areas where weed growth is thick. If travel-
ing in weeded areas is unavoidable, oper-
ate the engine alternately at partial throttle
and full throttle. Weeds tend to accumu-
late more at a steady speed and at trolling
speed. If weeds clog the jet intake or im-
peller area and cause cavitation, follow the
cleaning procedure above.
EJU34640Jumping the battery
If the watercraft battery has run down, the en-
gine can be started using a 12-volt booster
battery and jumper cables.
WARNING
EWJ00790
Battery electrolyte is poisonous and dan-
gerous, causing severe burns, etc. Elec-
trolyte contains sulfuric acid. Avoid
contact with skin, eyes, or clothing.
Antidotes
External: Flush with water.
Internal: Drink large quantities of water or
milk. Follow with milk of magnesia, beatenegg, or vegetable oil. Call a physician im-
mediately.
Eyes: Flush with water for 15 minutes and
get prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flames, cigarettes, etc., well away.
If using or charging the battery in an en-
closed space, make sure that it is well ven-
tilated. Always shield your eyes when
working near batteries.
KEEP OUT OF THE REACH OF CHILDREN.
EJU34651Connecting the jumper cables
(1) Connect the positive (+) jumper cable to
the positive (+) battery terminals of both
batteries.
(2) Connect one end of the negative (–)
jumper cable to the negative (–) battery
terminal of the booster battery.
(3) Connect the other end of the negative (–)
jumper cable to an unpainted bolt on the
cylinder head.
CAUTION:
ECJ00680
Do not connect the end of the negative (–)
jumper cable to the negative (–) battery
terminal of the watercraft battery! Make
sure that all connections are secure and
correct before attempting to start the en-
1Positive (+) jumper cable
2Booster battery
3Negative (–) jumper cable
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