2018 YAMAHA SUPERJET service

Care and storage
54
EJU33484
Long-term storage
WARNING
EWJ00321
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 easily by the owner.
EJU40763Cleaning
(1) Flush the cooling water passages. (See
page 50 for information on flushing the
cooling water passages.)
TIP:
If you will be storing the watercraft for a pro-
longed period, such as winter storage, top off
the fuel tank with fresh gasoline and add fuel
stabilizer and conditioner to the fuel tank ac-
cording to the manufacturer’s instruction be-
fore starting the engine.
(2) Clean the watercraft. (See page 51 for in-
formation on cleaning the watercraft.)
Wax the hull with a non-abrasive wax.
EJU40795Lubrication
Use a suitable marine grease applicator and
spray a rust inhibitor between the inner and
outer cables to lubricate the cables and
purge out any dirt and moisture.
To keep moving parts sliding or rotating
smoothly, lubricate them with water-resistant
grease.
Throttle cable (carburetor end) and choke
cable (carburetor end)
Throttle cable (throttle lever end)
Squeeze the throttle lever and remove the
seal. Spray a rust inhibitor into the outer ca-
ble. Refit the seal securely.
Recommended water-resistant grease:
YAMALUBE MARINE
GREASE/Yamaha Grease A
1Seal
UF4D74E0.book Page 54 Tuesday, March 21, 2017 9:35 AM

Maintenance
59
EJU40831Periodic maintenance chart
The periodic maintenance chart gives general guidelines for periodic maintenance. Have a
Yamaha dealer perform the checks in the following chart. However, maintenance may need
to be performed more frequently depending on your operating conditions. If you have any
questions, consult a Yamaha dealer.
This “ ” mark indicates maintenance that you may do yourself.
This “ ” mark indicates items to be checked and serviced by a Yamaha dealer.
Item OperationInitial Thereafter every
Page 10
hours50 hours100
hours200
hours
6
months12
months12
months24
months
Spark plugsCheck, clean, replace 60
Lubrication pointsLubricate 54
Intermediate
housingLubricate 61
Fuel systemCheck —
Fuel filterCheck 61
Check, replace —
Fuel tankCheck, clean —
CarburetorCheck, adjust —
Engine idling
speedCheck, adjust 62
Carburetor throttle
shaftCheck —
Bilge strainerClean —
ImpellerCheck —
Jet thrust nozzle
angleCheck, adjust —
Handlebar pivot
shaftCheck, adjust —
Steering frictionCheck, adjust —
Steering masterCheck, adjust —
Throttle cableCheck, adjust —
Choke cableCheck, adjust 61
BatteryCheck, charge —
Rubber couplingCheck —
Engine mountCheck —
Nuts and boltsCheck —
UF4D74E0.book Page 59 Tuesday, March 21, 2017 9:35 AM

Maintenance
60
EJU3437AChecking the spark plugs
WARNING
EWJ00351
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.
Remove and check the condition of the spark
plugs.
The condition of a spark plug can indicate
something about the condition of the engine.
For example, if the center electrode portion 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.
To remove a spark plug:
(1) Remove the hood. (See page 23 for hood
removal and installation procedures.)
(2) Remove the spark plug cap.
(3) Remove the spark plug, and then check
the condition of the spark plug and the
spark plug gap. If the electrode portion is
significantly discolored, if electrode ero-
sion becomes excessive, if carbon and
other deposits are excessive, or if the
spark plug gap is not within the specified
range, replace the spark plug.
TIP:
When the engine is operating normally, the
color of the spark plug electrode portion will
be a medium-to-light tan.
To install a spark plug:
(1) Wipe off any dirt from the threads, insu-
lator, and gasket surface of the spark
plug.
(2) Install the spark plug, and then tighten it
to the specified torque.
TIP:
If a torque-wrench is not available when you
are reinstalling a spark plug, a good estimate
of the correct torque is 1/12 turn past finger-
tight. When you are installing a new spark
plug, a good estimate of the correct torque is
1/2 to 2/3 turn past finger-tight.
(3) Wipe off any water or dirt inside the
spark plug cap.
1Insulator
2Electrode
3Spark plug gap
Specified spark plug:
BR7HS
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Tightening torque:
Spark plug:
25.0 N·m (2.55 kgf·m, 18.4 lb·ft)
UF4D74E0.book Page 60 Tuesday, March 21, 2017 9:35 AM

Trouble recovery
64
EJU34562
Troubleshooting
If you have any trouble with your watercraft, use the troubleshooting chart to check for the
possible cause.
If you cannot find the cause, consult a Yamaha dealer.
EJU34576Troubleshooting 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
19
Fuse Burned out Replace fuse and
check wiring67
Battery Run down Recharge 51
Poor terminal con-
nectionsTighten as required
51
Terminal corroded Clean or replace 51
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”21
Fuel Empty Refill as soon as pos-
sible28
Stale or contaminat-
edHave serviced by
Yamaha dealer—
Fuel tank Water or dirt present Have serviced by
Yamaha dealer—
Spark plug Fouled or defective Replace 60
Spark plug
capNot connected or
looseConnect properly
60
Crankcase Filled with water Have serviced by
Yamaha dealer69
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer61
Choke Knob moves back on
its ownTighten choke knob
adjusting nut61
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Trouble recovery
65
Engine runs irregu-
larly or stallsFuel Empty Refill as soon as pos-
sible28
Stale or contaminat-
edHave serviced by
Yamaha dealer—
Too much oil in fuel
mixing ratioCorrect fuel-to-oil ra-
tio to 50:128
Choke Knob is left pulled Push fully in 21
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer61
Fuel tank Water or dirt present Have serviced by
Yamaha dealer—
Spark plug Fouled or defective Replace 60
Incorrect heat range Replace 60
Gap incorrect Replace 60
Spark plug
capNot connected or
looseConnect properly
60
Cracked, torn or
damagedHave serviced by
Yamaha dealer—
Electrical wir-
ingLoose electrical con-
nectionsHave serviced by
Yamaha dealer—
Carburetor Incorrect idle adjust-
mentHave serviced by
Yamaha dealer—
Clogged Have serviced by
Yamaha dealer61
Watercraft slow or
loses powerCavitation Jet intake clogged Clean 66
Impeller damaged or
wornHave serviced by
Yamaha dealer66
Engine over-
heatedJet intake clogged Clean
66
Fuel filter Clogged Have serviced by
Yamaha dealer61
Spark plug Fouled or defective Replace 60
Incorrect heat range Replace 60
Gap incorrect Replace 60
Spark plug
capsNot connected or
looseConnect properly
60
Fuel Stale or contaminat-
edHave serviced by
Yamaha dealer— TROUBLE POSSIBLE CAUSE REMEDY PAGE
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Trouble recovery
69
EJU34735Submerged watercraft
If the watercraft is submerged or flooded with
water, drain the bilge water from the engine
compartment. Then, have a Yamaha dealer
service the watercraft as soon as possible.
(1) Remove the watercraft from the water,
and then remove the hood.
(2) Turn the fuel cock knob to “OFF”.
(3) Turn the watercraft over far enough to
drain the bilge water from the engine
compartment. NOTICE: 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.
[ECJ00702]
(4) Turn the watercraft upright again.
(5) Have the watercraft serviced by a
Yamaha dealer as soon as possible.
NOTICE: Be sure to have a Yamaha
dealer inspect the watercraft. Other-
wise, serious engine damage could
result.
[ECJ00792]
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