2008 YAMAHA SUPERJET service

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
49
EJU33761
Maintenance and adjustments
Periodic inspection, adjustment, and lubrica-
tion will keep your watercraft in the safest and
most efficient condition possible. Safety is an
obligation of the watercraft owner. Proper
maintenance must be carried out to keep the
exhaust emission and sound levels within the
regulated limits. The most important points of
watercraft inspection, adjustment, and lubri-
cation are explained on the following pages.
See a Yamaha dealer for genuine Yamaha re-
placement parts and optional accessories de-
signed for your watercraft.
Remember, failures that are the result of the
installation of parts or accessories which are
not qualitatively equivalent to genuine
Yamaha parts are not covered by the limited
warranty.
Maintenance, replacement, or repair of the
emission control devices and system may
be performed by any marine SI engine re-
pair establishment or individual. Warranty
repair, however, must be performed at an
authorized Yamaha marine dealership.
WARNING
EWJ00310

Be sure to shut the engine off when you
perform maintenance unless otherwise
specified, otherwise an accident or inju-
ry could result from unexpected opera-
tion, 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
components could fail or stop operating
correctly, which could result in an acci-
dent.

Modifications to this watercraft not ap-
proved by Yamaha may cause loss of
performance or excessive noise and ex-
haust emissions, or render it unsafe foruse. Consult a Yamaha dealer before at-
tempting any modifications.
EJU33780Owner’s/operator’s manual and tool
kit
It is advisable to always carry the owner’s/op-
erator’s manual and tool kit with you whenev-
er you use the watercraft. For your
convenience, a storage pouch is provided on
the watercraft for the manual and tool kit.
NOTE:
To protect these materials from water dam-
age, it would be a good idea to put them in a
waterproof bag.
The service information included in this man-
ual is intended to provide you, the owner, with
the necessary information for completing your
own preventive maintenance and minor re-
pairs. The tools provided in the tool kit are suf-
ficient for this purpose, except that a torque
1Storage pouch
UF2F70E0.book Page 49 Tuesday, April 17, 2007 9:56 AM

Maintenance and care
53
EJU34201Checking the fuel system
WARNING
EWJ00370
Gasoline is highly flammable and explo-
sive. Failure to check for and repair any
fuel leakage could result in a fire or explo-
sion. A fire or explosion can cause severe
injury or death. Shut the engine off. Do not
smoke. Avoid spilling gasoline.
Check the fuel system for leaks, cracks, and
malfunctions. If any problem is found, do the
necessary repair or replacement as required.
If repair is necessary, consult a Yamaha deal-
er.
Check:

Carburetor for leakage.

Fuel tank filler cap and seal for damage.

Fuel in fuel tank for water and dirt.

Fuel tank for damage, cracks, and leakage.

Fuel hoses and joints for damage, cracks,
and leakage.

Fuel filter for leakage.

Fuel cock for leakage.

Air vent check valve for leakage.EJU34220Fuel filter
This watercraft is equipped with a one-piece,
disposable fuel filter. The fuel filter should be
replaced after the initial 10 hours or first
month of operation and every 200 hours or 24
months thereafter, or if water is found in the fil-ter. Have a Yamaha dealer replace the fuel fil-
ter if necessary.
WARNING
EWJ00360
Do not try to replace the fuel filter yourself.
An incorrectly installed filter can leak gas-
oline, which could result in a fire or explo-
sion. If necessary, have a Yamaha dealer
replace the fuel filter.
EJU34230Fuel tank
Check the fuel tank for leakage and for water
in the tank. If water is found in the fuel system,
or if the fuel tank needs to be cleaned, have a
Yamaha dealer service the watercraft.
EJU34321Checking the jet thrust nozzle angle
Check the handlebars and jet thrust nozzle for
smooth operation.
1Fuel filter
1Fuel tank
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Maintenance and care
54
Turn the handlebars as far as possible to the
right and left and check that the difference of
distances A and B between the jet thrust noz-
zle and the nozzle is within specification.
If the steering is stiff or misadjusted, have a
Yamaha dealer service it.
EJU34331Adjusting the steering friction
The amount of friction in the steering can be
adjusted to suit operator preference.To adjust the steering friction:
(1) Lift the steering pole and support it with
the lock pin.
(2) Remove the four screws, and then re-
move the handlebar cover.
(3) Turn the handlebars so that the left han-
dlebar grip is facing down. Difference of A and B:
Maximum 5 mm (0.20 in)
1Steering pole
2Lock pin
1Adjusting nut
2Locknut
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Maintenance and care
56
steering column, and then tighten it to the
specified torque.
NOTE:
Do not install the steering cable pivot bolt in
the outermost hole in the steering column.
(5) Connect the steering cable joint to the
steering cable pivot bolt.(6) Install the steering pole cover, and then
install the two screws.
EJU34361Checking and adjusting the throttle
cable
Check that the throttle cable moves back to
the set position smoothly and that the throttle
lever free play is within specification.
Squeeze and release the throttle lever. If the
throttle lever does not return smoothly, have a
Yamaha dealer service it.
If the specified throttle lever free play cannot
be obtained as described below, have a
Yamaha dealer make the adjustment.
(1) Remove the four screws, and then re-
move the handlebar cover.
(2) Loosen the locknut.
(3) Adjust the free play by turning the adjust-
er.
1Nozzle angles
1Nozzle angles
2Steering cable pivot bolt positions
Standard steering cable pivot bolt posi-
tion:
P2
Tightening torque:
Steering cable pivot bolt:
5.4 Nm (4.0 ft-lb) (0.55 kgf-m)
1Locknut
2Adjuster
3Throttle lever free play
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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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Trouble recovery
63
EJU34560
Troubleshooting
If you have any trouble with your watercraft, use this section to check for the possible cause.
If you cannot find the cause, or if the procedure for replacement or repair is not described in
this owner’s/operator’s manual, have a Yamaha dealer perform the necessary service.
EJU34570Troubleshooting chart
TROUBLE POSSIBLE CAUSE REMEDY PAGE
Engine does not
start (Starter motor
does not turn over)Engine shut-
off switchClip not in place Install clip
19
Fuse Burned out Replace fuse and
check wiring67
Battery Run down Recharge 60
Poor terminal con-
nectionsTighten as required
60
Terminal corroded Clean 48
Starter motor Faulty Have serviced by
Yamaha dealer—
Engine does not
start (Starter motor
turns over)Fuel cock Turned to “OFF”Turn fuel cock knob to
“ON”18
Fuel Empty Refill as soon as pos-
sible26
Stale or contaminat-
edHave serviced by
Yamaha dealer53
Fuel tank Water or dirt present Have serviced by
Yamaha dealer53
Spark plug Fouled or defective Clean or replace 57
Spark plug
capNot connected or
looseConnect properly
57
Crankcase Filled with water Crank engine with
plug out until clean68
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer53
Choke Knob moves back on
its ownTighten choke knob
adjusting nut59
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Trouble recovery
64
Engine runs irregu-
larly or stallsFuel Empty Refill as soon as pos-
sible26
Stale or contaminat-
edHave serviced by
Yamaha dealer53
Too much oil in fuel
mixing ratioCorrect fuel-to-oil ra-
tio to 50:125
Choke Knob is left pulled Push fully in 20
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer53
Fuel tank Water or dirt present Have serviced by
Yamaha dealer53
Spark plug Fouled or defective Replace 57
Incorrect heat range Replace 57
Gap incorrect Adjust 57
Spark plug
capLoose Connect properly 57
Cracked, torn or dam-
agedReplace
—
Electrical wir-
ingLoose electrical con-
nectionsTighten or connect
properly—
Carburetor Incorrect idle adjust-
mentAdjust idle
61
Clogged Have serviced by
Yamaha dealer61
Watercraft slow or
loses powerCavitation Jet intake clogged Clean 65
Impeller damaged or
wornHave serviced by
Yamaha dealer65
Engine over-
heatedJet intake clogged Clean
65
Fuel filter Clogged Have serviced by
Yamaha dealer53
Spark plug Fouled or defective Replace 57
Incorrect heat range Replace 57
Gap incorrect Adjust 57
Spark plug
capsLoose Connect properly
57
Fuel Stale or contaminat-
edHave serviced by
Yamaha dealer53 TROUBLE POSSIBLE CAUSE REMEDY PAGE
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