spark plugs YAMAHA SUPERJET 2003 Owners Manual

2-2
E
1Fire extinguisher container
2Fuel cock knob
Use to select either normal or reserve fuel flow
from the fuel tank to the carburetors, or to shut
off fuel flow.
3Choke knob
Use to start a cold engine.
4Clip
Insert into the engine shut-off switch to enable
starting of the engine.
Remove to stop the engine or prevent acci-
dental star ting of the engine or unauthorized
use of the watercraft.
5Start switch
Push to start the engine.
6Throttle lever
Use to accelerate and decelerate.
7Engine shut-off switch
Remove the clip to stop the engine and dis-
able it from starting.8Engine stop switch
Push to stop the engine normally.
9Engine shut-off cord (lanyard)
Attach to wrist so that the engine stops if the
operator falls off the watercraft.
0Bow
AFuel tank
BBattery
CSilencer
Prevents water from getting into the engine
and reduces air intake noise.
DSpark plugs/Spark plug caps
EMuffler
FWater separator
Traps water from the breather hose to the fuel
tank.
GFuel filter
HFlush hose connector
Use to flush the engine cooling water pas-
sages.
IElectrical box
Protects electrical components from water.
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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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E
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MAINTENANCE AND
CARE
Storage ...................................................... 4-1
Flushing the cooling system .................. 4-1
Lubrication .............................................. 4-3
Fuel system ............................................ 4-5
Battery .................................................... 4-5
Cleaning the watercraft .......................... 4-6
Maintenance and adjustments .............. 4-7
Owner’s/Operator’s Manual and
tool kit ..................................................... 4-8
Periodic maintenance chart ................... 4-9
Inspecting the fuel system ................... 4-10
Inspecting the jet thrust nozzle
angle ..................................................... 4-12
Inspecting and adjusting the throttle
cable ..................................................... 4-12
Cleaning and adjusting the spark
plugs ..................................................... 4-13
Lubrication points ................................. 4-14
Adjusting the choke cable .................... 4-16
Inspecting the battery .......................... 4-17
Adjusting the carburetor ...................... 4-19
Replacing the fuse ............................... 4-20
Adjusting the steering friction .............. 4-20
Adjusting the jet thrust nozzle angle ... 4-21
Specifications ........................................ 4-23
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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 before installing the
spark plug. Adjust the gap to specification if
necessary.
To reinstall spark plug:
1. Clean the gasket surface.
2. Wipe any dirt from the threads of the
spark plug.
3. Screw the spark plug to the correct
torque. Standard spark plug: BR7HS
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Spark plug torque:
25 N·m (2.5 kgf·m, 18 ft·lb)
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Submerged watercraft
If the watercraft is submerged or flooded
with water, follow the procedure below and
consult a Yamaha dealer as soon as possi-
ble. Failure to do so may result in serious
engine damage!
In an emergency:
1. Beach the watercraft and remove the
hood. Turn the watercraft over far
enough to drain the water from the
engine compartment.
CAUTION:@ Turning the watercraft on its side with the
hood removed could cause damage to
the steering pole. Use two people to pro-
vide enough support to make sure that
the steering pole is not damaged.
@
2. Turn the watercraft upright again.
3. Turn the fuel cock knob to “OFF.”
4. Remove the spark plugs and dry them
with a cloth.
5. Without reinstalling the spark plugs,
crank the engine until all water in the cyl-
inders has been drained.
6. Install the spark plugs and the hood.
7. Turn the fuel cock knob to “ON.”
8. Launch the watercraft into the water, and
then run the engine for at least 10 min-
utes. If the engine does not start, repeat
steps 3–8.
9. Turn the engine off.
10. Turn the fuel cock knob to “OFF,” remove
the silencer cap, and then spray a rust
inhibitor into the carburetor while crank-
ing the engine.
11. Have the watercraft inspected by a
Yamaha dealer as soon as possible.
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Index
2-stroke engine oil ................................... 3-2
A
Adjusting the carburetor ........................ 4-19
Adjusting the choke cable ..................... 4-16
Adjusting the jet thrust nozzle angle ..... 4-21
Adjusting the steering friction ................ 4-20
Adjusting the trolling speed ................... 4-19
B
Battery .............................................. 3-8, 4-5
Beaching the watercraft ........................ 3-30
Bilge ........................................................ 3-7
Boarding and starting in deep water ..... 3-22
Boarding and starting in shallow
water ..................................................... 3-24
C
Capsized watercraft .............................. 3-26
Choke knob ............................................. 2-6
Cleaning and adjusting the spark
plugs...................................................... 4-13
Cleaning the jet intake and impeller ........ 5-3
Cleaning the watercraft ........................... 4-6
Connecting the jumper cables................. 5-5
Cooling water pilot outlet ................ 2-7, 3-12
Cruising limitations .................................. 1-7
E
Emergency procedures ........................... 5-3
Engine break-in ..................................... 3-13
Engine compartment ............................... 3-6
Engine overheat warning system ............ 2-9
Engine serial number .............................. 1-1
Engine shut-off cord (lanyard) ............... 3-11
Engine shut-off switch ............................. 2-5
Engine stop switch .................................. 2-5
Enjoy your watercraft responsibly ......... 1-13
F
Filling the fuel tank .................................. 3-4
Fire extinguisher...................................... 3-9
Flushing the cooling system .................... 4-1
Fuel and oil.............................................. 3-1
Fuel cock knob ........................................ 2-4Fuel filter ............................................... 4-11
Fuel system ......................................3-6, 4-5
Fuel tank ............................................... 4-11
Fuel tank filler cap ................................... 2-4
G
Gasohol ................................................... 3-2
Gasoline .................................................. 3-1
Getting to know your watercraft ............ 3-19
H
Hazard information ................................ 1-11
Hood........................................................ 2-3
Hull Identification Number (HIN).............. 1-1
I
Identification numbers ............................. 1-1
Important labels ....................................... 1-2
Inspecting and adjusting the throttle
cable...................................................... 4-12
Inspecting the battery ............................ 4-17
Inspecting the fuel system ..................... 4-10
Inspecting the jet thrust nozzle angle .... 4-12
J
Jet unit................................................... 3-11
Jumping the battery ................................. 5-4
K
Kneeling ................................................ 3-25
L
Label location .......................................... 1-2
Learning to operate your watercraft ...... 3-19
Leaving the watercraft ........................... 3-18
Limitations on who may operate the
watercraft ................................................ 1-6
Location of main components ................. 2-1
Lubrication............................................... 4-3
Lubrication points .................................. 4-14
M
Maintenance and adjustments ................ 4-7
Mixing fuel and oil ................................... 3-3
O
Operating positions ............................... 3-25
Operating your watercraft ...................... 3-19
Operation .............................................. 3-13
Operation of controls and other
functions .................................................. 2-3
UF1N71.book Page 1 Tuesday, June 4, 2002 3:34 PM