2007 YAMAHA SUPERJET engine

Maintenance and care
56
(2) Adjust the free play by loosening the lock-
nut and turning the adjuster.
EJU34370Cleaning and adjusting the spark
plugs
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.
1Locknut
2Adjuster
3Throttle lever free play
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
60
(1) Remove all of the battery caps.
(2) If the electrolyte level is low, add distilled
water to raise it to the specified level.
(3) Set the charging rate to 1.9 ampere and
charge the battery slowly until the explo-
sive gases are discharged vigorously
from the battery cells.
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.
(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, poor
engine 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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Specifications
61
EJU34540
Specifications
Watercraft capacity:
Maximum people on board:
1 person
Dimensions:
Length:
2240 mm (88.2 in)
Width:
680 mm (26.8 in)
Height:
660 mm (26.0 in)
Dry weight:
132.0 kg (291 lb)
Performance:
Maximum output (according to ISO 8665/SAE
J1228):
48.5 kW@6250 r/min
Maximum fuel consumption:
29.0 L/h (7.7 US gal/h) (6.4 Imp.gal/h)
Crusing range at full throttle:
0.62 hour
Trolling speed:
1300 ±50 r/min
Engine:
Engine type:
2-stroke
Number of cylinders:
2
Engine displacement:
701.0 cm³ (42.78 cu.in)
Bore & stroke:
81.0 × 68.0 mm (3.19 × 2.68 in)
Compression ratio:
7.20 :1
Lubrication system:
Pre-mixed fuel and oil
Cooling system:
Water
Starting system:
Electric
Ignition system:
C.D.I.
Spark plug:
BR7HS
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Battery capacity:
12 V19.0 AhCharging system:
Flywheel magneto
Drive unit:
Propulsion system:
Jet pump
Jet pump type:
Axial flow, single stage
Impeller rotation:
Counter clockwise
Jet thrust nozzle angle:
18.5, 20.5, 22.5, 24.5
Fuel and oil:
Recommended fuel:
Regular unleaded gasoline
Minimum octane rating (PON):
86
Minimum octane rating (RON):
90
Recommended engine oil:
YAMALUBE 2-W or TC-W3 outboard motor
oil or equivalent
Fuel mixing ratio (fuel to oil):
50 :1
Fuel tank total capacity:
18.0 L (4.8 US gal) (4.0 Imp.gal)
Fuel tank reserve capacity:
5.5 L (1.5 US gal) (1.2 Imp.gal)
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Trouble recovery
62
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
20
Fuse Burned out Replace fuse and
check wiring66
Battery Run down Recharge 59
Poor terminal con-
nectionsTighten as required
59
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”19
Fuel Empty Refill as soon as pos-
sible26
Stale or contaminat-
edHave serviced by
Yamaha dealer52
Fuel tank Water or dirt present Have serviced by
Yamaha dealer52
Spark plug Fouled or defective Clean or replace 56
Spark plug
capNot connected or
looseConnect properly
56
Crankcase Filled with water Crank engine with
plug out until clean67
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer52
Choke Knob moves back on
its ownTighten choke knob
adjusting nut58
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Trouble recovery
63
Engine runs irregu-
larly or stallsFuel Empty Refill as soon as pos-
sible26
Stale or contaminat-
edHave serviced by
Yamaha dealer52
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 dealer52
Fuel tank Water or dirt present Have serviced by
Yamaha dealer52
Spark plug Fouled or defective Replace 56
Incorrect heat range Replace 56
Gap incorrect Adjust 56
Spark plug
capLoose Connect properly 56
Cracked, torn or dam-
agedReplace
—
Electrical wir-
ingLoose electrical con-
nectionsTighten or connect
properly—
Carburetor Incorrect idle adjust-
mentAdjust idle
60
Clogged Have serviced by
Yamaha dealer60
Watercraft slow or
loses powerCavitation Jet intake clogged Clean 64
Impeller damaged or
wornHave serviced by
Yamaha dealer64
Engine over-
heatedJet intake clogged Clean
64
Fuel filter Clogged Have serviced by
Yamaha dealer52
Spark plug Fouled or defective Replace 56
Incorrect heat range Replace 56
Gap incorrect Adjust 56
Spark plug
capsLoose Connect properly
56
Fuel Stale or contaminat-
edHave serviced by
Yamaha dealer52 TROUBLE POSSIBLE CAUSE REMEDY PAGE
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Trouble recovery
64
EJU34620
Emergency procedures EJU34630Cleaning the jet intake and impeller
If weeds or debris get caught in the jet intake
or impeller, cavitation can occur, causing jet
thrust to decrease even though engine speed
rises. If this condition is allowed to continue,
the engine will overheat and may seize. If
there is any sign that the jet intake or impeller
is clogged with weeds or debris, return to
shore and check the intake and impeller. Al-
ways stop the engine before beaching the wa-
tercraft.
WARNING
EWJ00780
Before attempting to remove weeds or de-
bris from the jet intake or impeller area,
shut the engine off and remove the clip
from the engine shut-off switch. Severe in-
jury or death could result from coming incontact with the rotating parts of the jet
pump.
CAUTION:
ECJ00650
If weeds or debris get caught in the jet in-
take, do not operate the watercraft above
trolling speed until they have been re-
moved.
(1) Turn the watercraft on its side as shown.
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Trouble recovery
65
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.
EJU34650Connecting 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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Trouble recovery
66
gine. Any wrong connection could dam-
age the electrical system.
(4) Start the engine, and then disconnect the
jumper cables by reversing the steps
above.
CAUTION:
ECJ00690

Never push the start switch while the en-
gine is running.

Do not operate the start switch for more
than 5 seconds, otherwise the battery
will be discharged and the engine will
not start. Also, the starter motor could
be damaged. If the engine does not start
in 5 seconds, release the start switch,
wait 15 seconds, and then try again.
EJU34670Replacing the fuse
The fuse is located in the electrical box.
To replace the fuse:
(1) Remove the cap, and then pull out the
red lead to pull out the fuse holder from
the electrical box.
(2) Open the fuse holder and replace the
fuse with one of the correct amperage.
WARNING
EWJ00800
Do not use fuses of higher amperage than
recommended. Substitution with a fuse
that has an improper rating can cause ex-
tensive electrical system damage and pos-
sible fire.
EJU34700Towing the watercraft
If the watercraft becomes inoperative in the
water, it can be towed to shore.
If the watercraft must be towed in an emer-
gency using a towline, the operator should
ride the watercraft, holding onto the handle-
bars and supporting his or her body weight on
the riding tray. This will help keep the bow of
the watercraft out of the water.
CAUTION:
ECJ00710

Tow the watercraft at 5 mph (8 km/h) or
less, otherwise water could enter the en-
gine through the exhaust passages or
through the air intake and flood the en-
gine compartment if it is towed too fast.

Tow the watercraft using the bow rope
hole only.
1Electrical box
2Fuse holder
3Cap
4Fuse
Fuse amperage:
10 A
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