2005 YAMAHA SUPERJET Owners Manual

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EJU01891
Inspecting the jet thrust nozzle
angle
Check for smooth operation of the handle-
bars and jet thrust nozzle.
Turn the handlebars as far as possible to
the right and left and check that the distance
between the jet thrust nozzle and the hull
are equal on right and left sides.
If steering is stiff or misadjusted, have a
Yamaha dealer service it.Distance A and B: A=B
EJU01375
Inspecting and adjusting the
throttle cable
Check that the throttle cable moves back
to the set position smoothly and that free
play is within specification.
1. Squeeze and release the throttle lever. If
the lever does not return smoothly, have
a Yamaha dealer service it.
2. Adjust free play a by loosening the lock-
nut 1 and turning the adjuster 2.
Throttle lever free play:
7–10 mm (0.28–0.39 in)
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EJU13431
Cleaning and adjusting the
spark plugs
The spark plug is an important engine
component and is easy to inspect. The con-
dition of the spark plug can indicate some-
thing 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 diagnose any problems
yourself. Have a Yamaha dealer service the
watercraft.
Remove and inspect the spark plug peri-
odically; heat and deposits will cause the
spark plug to slowly break down and erode.
If electrode erosion becomes excessive, or if
carbon and other deposits are excessive,
replace the spark plug with the specified
plug.
Measure the spark plug gap a with a
wire thickness gauge. Replace the spark
plug or adjust the gap to specification if nec-
essary.
To install the 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.Standard spark plug: BR7HS
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Spark plug tightening torque:
25 N·m (2.5 kgf·m, 18 ft·lb)
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NOTE:@
Wipe off any water on the spark plug or
inside the cap before installing the spark
plug cap. Push the spark plug cap down
until it is securely installed.

If a torque wrench is not available when
you are installing a new spark plug, a
good estimate of the correct torque is 1/4
turn to 1/2 turn past finger tight with the
spark plug wrench included in the tool kit.
Have the spark plug adjusted to the cor-
rect torque with a torque wrench as soon
as possible.
@
WARNING@ Be careful not to damage the insulator
when removing or installing a spark plug.
A damaged insulator could allow sparks
to escape, which could lead to an explo-
sion or fire.
@
EJU13021
Lubrication 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)
Pull the throttle lever and remove the
seal1. Spray a rust inhibitor into the
outer cable. Refit the seal securely. Recommended water resistant grease:
Yamaha Marine Grease/
Yamaha Grease A
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Steering cable ball joint (handlebar end)

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

Steering cable ball joint (nozzle end)

Steering cable inner wire (nozzle end)

Steering handle pivot shaft
Lubrication of the steering handle pivot
shaft requires disassembly of steering
components. Have a Yamaha dealer lubri-
cate it.

Steering nozzle pivot bolts (collars)
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Intermediate housing
Using a grease gun, fill the intermediate
housing with water-resistant grease
through the grease nipple.
Grease quantity:
Initial 10 hours or 1 month:
20.0–22.0 cm
3 (0.67–0.74 oz)
Every 100 hours or 12 months:
3.0–5.0 cm
3 (0.10–0.33 oz)
EJU01261
Adjusting the choke cable
Check that the choke cable is properly
adjusted.
1. Pull the choke knob out until it stops, and
then release the knob. The knob should
not move.
2. If the choke knob moves back on its own,
tighten the choke knob adjusting nut 1
slightly. If the knob is difficult to move,
loosen the adjusting nut slightly.
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EJU19710
Inspecting the battery
Check the level of the battery electrolyte
and make sure that the negative and posi-
tive leads are securely tightened.
WARNING@
Battery electrolyte is poisonous and
dangerous, causing severe burns, etc.
Electrolyte contains sulfuric acid.
Avoid contact with skin, eyes, or cloth-
ing.
Antidotes
External: Flush with water.
Internal: Drink large quantities of water
or milk. Follow with milk of magnesia,
beaten egg, or vegetable oil. Call phy-
sician immediately.
Eyes: Flush with water for 15 minutes
and get prompt medical attention.
Batteries produce explosive gases.
Keep sparks, flame, cigarettes, etc.,
well away. If using or charging the bat-
tery in an enclosed space, make sure
that it is well ventilated. Always shield
your eyes when working near batter-
ies.
KEEP OUT OF THE REACH OF CHIL-
DREN.

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.
@
CAUTION:@
Be careful not to place the battery on
its side.

Be sure to remove the battery from the
battery compartment when adding
electrolyte or charging the battery.
@
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To replenish the battery:
1. Make sure that the electrolyte level is
between the upper 1 and lower 2 level
marks.
2. Refill the battery with distilled water if
necessary.
CAUTION:@ Normal tap water contains minerals that
are harmful to a battery. Use only dis-
tilled water for replenishing the battery.
@
To recharge the battery:
CAUTION:@ Do not attempt to charge a battery hast-
ily. Battery life could be shortened.
@
It is recommended to have a Yamaha
dealer charge the battery. If you charge the
battery yourself, carefully read the battery
charger instructions before charging and fol-
low the points below.
1. Remove all caps from the battery cell.
2. Add distilled water to the specified level if
the electrolyte level is low.
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 connect the battery terminals:
1. Make sure that the connections are cor-
rect when you install the battery in the
watercraft.
2. Make sure that the breather hose is
properly connected and that it is not
damaged or obstructed.
3. Make sure that the battery is securely
held in place.
1Positive (+): Red lead
2Negative (–): Black lead
3Breather hose
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EJU01109
Adjusting the carburetor
The carburetor is a vital part of the engine
and requires very sophisticated adjustment.
Most adjusting should be left to a Yamaha
dealer who has the professional knowledge
and experience to perform it. However, the
operator may adjust the trolling speed as
part of the usual maintenance routine.
CAUTION:@ The carburetor was set at the Yamaha
factory after many tests. If the settings
are disturbed by someone who does not
have the necessary technical knowledge,
poor engine performance and damage
may result.
@
EJU01303
Adjusting the trolling speed
1. Put the watercraft in the water.
2. Start the engine and warm it up for 1 or
2 minutes. Using a diagnostic tachome-
ter, adjust the engine speed to specifica-
tion.
3. Turn the throttle stop screw 1 clockwise
to increase engine speed if necessary.
Turn it counterclockwise to decrease
engine speed if necessary.
Trolling speed: 1,250–1,350 r/min
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