2005 YAMAHA SUPERJET engine

3-3
E
EJU01276
Mixing fuel and oil
CAUTION:@
Avoid using any mixture of gasoline
and oil other than those designated.

Make sure gasoline and oil are thor-
oughly mixed in the correct ratio, oth-
erwise the following problems may
occur. Too little oil in the fuel mixing
ratio could result in major engine trou-
ble, such as seizure. Too much oil in
the fuel mixing ratio could result in
fouled spark plugs, smoky exhaust, or
heavy carbon deposits.
@
Pour 2-stroke engine oil 1 into a clean
container, and then add gasoline 2. To mix
them thoroughly, shake the container from
side to side.
Fuel mixing ratios (gasoline to oil)
Break-in period
(first two tankfuls): 25 : 1
After break-in: 50 : 1
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3-4
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EJU01277
Filling the fuel tank
CAUTION:@ Be careful when refueling. Avoid getting
water or other contaminants in the fuel
tank. Contaminated fuel can cause poor
running or engine damage.
@
1. Lift the steering pole and support it with
the lock pin.
2. Remove the hood.
3. Open the fuel tank filler cap, and slowly
add the premixed fuel to the fuel tank.
4. Stop filling when the fuel level just
reaches the bottom of the filler tube.
NOTE:@
The hood must be removed in order to
watch the fuel level in the fuel tank while
adding fuel.

Be careful not to spill fuel or overfill the
tank.

Do not fill into the filler tube because fuel
could overflow.
@
Fuel tank capacity:
Total: 18 L (4.8 US gal, 4.0 Imp gal)
Reserve: 5.5 L
(1.45 US gal, 1.21 Imp gal)
UF1N73.book Page 4 Monday, May 10, 2004 10:37 AM

3-5
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EJU01346
Pre-operation checks
EJU01347
Pre-operation check list
Before operating this watercraft, perform the checks in the following check list. See the
accompanying text in this chapter for details on how to perform the checks.
WARNING@ If any item in the pre-operation check list is not working properly, have it inspected
and repaired before operating the watercraft, otherwise an accident could occur.
@
NOTE:@ Pre-operation checks should be made thoroughly each time the watercraft is used. This pro-
cedure can be completed in a short time. It is worth the time spent to assure safety and reli-
ability.
@
ITEM ROUTINE PAGE
Engine compar tment Remove the hood to ventilate the engine com-
partment. Check for fuel vapors and loose elec-
trical connections.3-6
Bilge Check for water and fuel and remove if neces-
sary.3-8
Throttle lever Check that the throttle lever springs back
smoothly.3-10
Steering system Check for proper operation. 3-10
Fuel Check fuel level and add if necessary.
Check the hoses and tank for leakage.3-7
Water separator Check for water and drain if necessary. 3-7
Battery Check electrolyte level and battery condition. 3-8
Hood Check that the hood latches are properly
secured.2-3
Hull Check the hull for cracks or other damage. 3-6
Jet unit Check for debris and remove if necessary. 3-11
Fire extinguisher Check condition and replace if necessary. 3-9
Engine shut-off cord Check condition and replace if frayed or broken. 3-11
Switches Check the start switch, engine stop switch, and
engine shut-off switch for proper operation.3-12
Cooling water pilot outlet Check that water is discharged while the engine
is running and the watercraft is in the water.3-12
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3-6
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EJU01048
Pre-operation check points
EJU01278
Engine compartment
Ventilate the engine compartment, before
each use. To ventilate the engine compart-
ment, lift the steering pole and support it
with the stopper pin, then remove the hood.
Put the hood aside for a few minutes to allow
any fuel vapors to escape. Also, check for
loose electrical connections.
WARNING@ Failure to ventilate the engine compart-
ment could result in fire or explosion. Do
not start the engine if there is a fuel leak
or loose electrical connection.
@
EJU20560
Hull
Check the hull for cracks or other dam-
age. If any damage is found, have a Yamaha
dealer repair the watercraft.
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3-8
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EJU01280
Bilge
Check for moisture and fuel residue in the
bilge.
Excessive water in the bilge can splash
into the carburetor and engine which could
cause engine damage.
EJU19690
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.

Be sure to connect the breather hose
to the battery. Fire or explosion could
result if the breather hose is damaged,
obstructed, or not connected properly.
@
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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3-10
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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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EJU18352
Switches
CAUTION:@ Do not run the engine of the watercraft
for more than 15 seconds on land with-
out supplying water, otherwise the
engine may overheat.
@
Check the start switch, the engine stop
switch, and the engine shut-off switch for
proper operation.
Push the start switch 1 to start the
engine. As soon as the engine starts run-
ning, push the engine stop switch 2 to ver-
ify that the engine stops immediately.
Restart the engine, and then pull the engine
shut-off cord 5 to remove the clip 4 from
the engine shut-off switch 3 to 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.
UF1N73.book Page 12 Monday, May 10, 2004 10:37 AM