2008 YAMAHA SUPERJET engine

Operation
44
(5) Flush the cooling system to prevent it
from clogging with salt, sand, or dirt. (See
page 46 for flushing procedures.)
(6) Drain residual water from the exhaust
system by alternately squeezing and re-
leasing the throttle lever for 10 to 15 sec-
onds while the engine is running.
CAUTION:
ECJ00561
Do not run the engine for more than 15
seconds without supplying water, other-
wise the engine could overheat.
(7) If the watercraft will be stored for a week
or more, lubricate internal engine compo-
nents to help prevent corrosion. (See
page 47 for lubrication procedures.)
(8) Rinse the engine and engine compart-
ment with a small amount of water.
CAUTION:
ECJ00570
Do not use high-pressure water when rins-
ing the engine or engine compartment as
severe engine 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 installing the hood.
EJU33420
Transporting
WARNING
EWJ00750
Always turn the fuel cock knob to “OFF”
when transporting the watercraft, other-
wise fuel could leak out into the engine or
engine compartment, which would create
a fire hazard.
Transport this watercraft using a special trail-
er that incorporates a hole into which the pin
can be inserted and locked after passing it
through the bow rope hole.
After securing the bow with the pin, secure the
stern with ropes or tie downs routed over the
1Pin
2Bow rope hole
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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
48
line in your eyes, get immediate medical
attention.

If any gasoline spills on your skin or
clothing, immediately wash the affected
area with soap and water and change
your clothes.
Draining the fuel system prevents buildup of
varnishes and other harmful deposits that re-
sult when gasoline sits for a long period of
time.
To drain the fuel system:
(1) Turn the fuel cock knob to “OFF”.
(2) Drain the fuel tank using a siphon.
EJU33680Battery
If the watercraft will not be used for more than
a month, remove the battery from the water-
craft and store it in a cool, dry place.
(1) Disconnect the negative (–) battery lead
first, then the positive (+) battery lead and
breather hose, and then remove the bat-
tery from the watercraft.
(2) Clean the battery casing using fresh wa-
ter.
(3) If the battery terminals are dirty or corrod-
ed, clean them with a wire brush.
(4) Fully charge the battery.
(5) Apply Yamaha Marine Grease or
Yamaha Grease A to the battery termi-
nals, and then store the battery in a cool,
dry place.
(6) Check the battery at least once every 2
months and fully charge it if necessary.
CAUTION:
ECJ00100
Always keep the battery charged. Storing
a discharged battery can cause permanent
battery damage.
To check the condition of the battery, check
the specific gravity of the electrolyte or mea-
sure 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 charge the bat-
tery. If you maintain the battery yourself, be
sure to read and follow the instructions provid-
ed with the battery tester and charger you
use.
EJU33700Cleaning the watercraft
Clean the watercraft before storing it for a long
period.
(1) Wash down the hull, handlebars, and jet
unit with fresh water.
(2) Rinse the engine and bilge area with
fresh water. Drain all of the water and
wipe up any remaining moisture with
clean, dry rags.
CAUTION:
ECJ00110
Do not use high-pressure water when rins-
ing the engine and bilge area as severe en-
gine damage could result.
(3) Spray the engine’s exterior with a rust in-
hibitor 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.
NOTE:
Do not use vinyl protectant on the riding tray,
because it will make it slippery.
Specific gravity (for reference):
1.28 at 20 °C (68 °F)
UF2F70E0.book Page 48 Tuesday, April 17, 2007 9:56 AM

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
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Maintenance and care
51
EJU33820Periodic maintenance chart
The following chart gives general guidelines for periodic maintenance. However, maintenance
may need to be performed more frequently depending on your operating conditions.
This “” mark indicates maintenance that you may do yourself.
This “” mark indicates work to be done by a Yamaha dealer.
Item OperationInitial Thereafter every
Page 10
hours50
hours100
hours100
hours200
hours
6
months12
months12
months24
months
Spark plugsCheck, clean, adjust 57
Lubrication pointsLubricate 58
Intermediate hous-
ingLubricate 58
Fuel systemCheck 53
Fuel filterCheck, clean, replace 53
Fuel tankCheck, clean 53
CarburetorCheck, adjust 61
Trolling speedCheck, adjust 61
Carburetor throt-
tle shaftCheck—
Cooling water pas-
sagesFlush
*46
Bilge strainerClean—
ImpellerCheck—
Jet thrust nozzle
angleCheck, adjust 53
Handlebar pivot
shaftCheck—
Steering frictionCheck, adjust 54
Throttle cableCheck, adjust 56
Choke cableCheck, adjust 59
BatteryCheck, charge 60
Rubber couplingCheck—
Engine mountCheck—
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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
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)
UF2F70E0.book Page 57 Tuesday, April 17, 2007 9:56 AM