engine YAMAHA FX 2003 Repair Manual

4-6
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NOTE:@ The condition of the battery can be known
by checking the specific gravity of the elec-
trolyte. However, you can also know the con-
dition of the battery by measuring the
voltage at both battery terminals. Charge
the battery if the voltage is less than
12 volts.
It is recommended to have a Yamaha dealer
check the specific gravity and to charge the
battery. If you maintain the battery yourself,
be sure to read and follow the instructions
provided with the battery tester and charger
you use.
@
EJU01093
Cleaning the watercraft
Clean the watercraft before storing it for a
long period.
1. Wash down the hull, handlebars, and
drive unit with fresh water.
2. Rinse the engine and bilge area with
fresh water. Drain off all water and wipe
up remaining moisture with clean, dry
rags.
3. Spray the engine’s exterior with a rust
inhibitor and lubricant.
4. Wax the hull with a non-abrasive wax.
5. Wipe all vinyl and rubber components,
such as the seat and engine compart-
ment seals, with a vinyl protectant. Specific gravity (for reference):
1.28 at 20 °C (68 °F)
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EJU01094
Maintenance and
adjustments
Periodic inspection, adjustment and lubri-
cation will keep your watercraft in the safest
and most efficient condition possible. Safety
is an obligation of the watercraft owner. The
most important points of watercraft inspec-
tion, adjustment and lubrication are
explained on the following pages.
See your Yamaha dealer for genuine
Yamaha replacement parts and optional
accessories designed for your watercraft.
Remember that failures that are the result
of the installation of parts or accessories
which are not qualitatively equivalent to gen-
uine Yamaha parts are not covered by the
limited warranty.
WARNING@
Be sure to turn off the engine when
you perform maintenance unless oth-
erwise specified, otherwise an acci-
dent or injury could result from
unexpected operation, moving parts,
or electric shock. If the owner is not
familiar with watercraft servicing, this
work should be done by a Yamaha
dealer. Improperly serviced compo-
nents could fail or stop operating cor-
rectly, which could result in an
accident.

Modifications to this watercraft not
approved by Yamaha may cause loss
of performance or excessive noise, or
render it unsafe for use. Consult a
Yamaha dealer before attempting any
changes.
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4-9
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EJU01355
Periodic maintenance chart
The following chart gives general guidelines for periodic maintenance. However, depend-
ing on your operating conditions maintenance may need to be performed more frequently.
PMC-F1B1(
) This mark indicates maintenance that you may do yourself.
(
❍) This mark indicates work to be done by a Yamaha dealer.
MAINTENANCE INTERVAL
INITIALTHEREAFTER
EVERYPA G E
10
hours50
hours100
hours100
hours200
hours
ITEM
6
months12
months12
months24
months
Spark plug Inspect, clean, adjust



4-16
Lubrication points Lubricate


4-18
Intermediate housing Lubricate❍
*1

*2

*2 4-20
Fuel system Inspect❍❍
4-10
Fuel tank Clean❍❍
4-10
Trolling speed Inspect, adjust❍❍❍
4-23
Throttle shaft Inspect❍❍
—
Cooling water passages Flush

*3 4-1
Water inlet strainer Inspect, clean❍❍
—
Bilge strainer Clean❍❍
—
Electric bilge pump strainer Inspect, clean❍❍
—
Impeller Inspect

*4❍❍
—
Jet thrust nozzle angle Inspect


4-14
Steering master Inspect❍❍❍
—
QSTS mechanism Inspect, adjust

*4❍❍
4-15
Shift cable and mechanism Inspect, adjust

*4❍❍
4-14
Throttle lever Check operation

*4 3-12
Throttle cable Inspect, adjust❍❍
4-14
Stern drain plugs Inspect, replace

*4❍❍
3-9
Battery Inspect

*5❍❍
—
Rubber coupling Inspect❍
—
Engine mount Inspect❍
—
Nuts and bolts Inspect❍❍❍
—
Air filter Inspect❍

4-13
Engine oil Replace❍❍❍
4-11
Engine oil filter Replace❍
—
Valve clearance Inspect, adjust❍
—
*1: Grease capacity: 33.0–35.0 cm3 (1.11–1.18 oz)
*2: Grease capacity: 6.0–8.0 cm3 (0.20–0.27 oz)
*3: After every use
*4: Before every use
*5: Inspect fluid level before every use
UF1B71.book Page 9 Tuesday, November 12, 2002 4:17 PM

4-10
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EJU01816
Inspecting the fuel system
WARNING@ Gasoline is highly flammable and explo-
sive. Failure to check for and repair any
fuel leakage could result in fire or explo-
sion. A fire or explosion can cause
severe injury or death. Shut off the
engine. Do not smoke. Avoid spilling
gasoline.
Fuel in hose is pressurized.
Fuel can spray out and cause injury or a
fire hazard if fuel line is disconnected.
Do not attempt to run engine with fuel
line disconnected.
Check the fuel system for leaks, cracks,
or malfunctions. If any problem is found,
consult a Yamaha dealer.
Check:

Fuel tank for water or dirt.

Fuel tank cap (seal) for damage.

Fuel tank for damage, cracks or leakage.

Fuel hose joint for leakage.

Fuel hose for cracks or other damage.

Air bleeding passages for leakage.
EJU01841
Fuel tank
Check the fuel tank 1 for leakage or
water in the tank. If water is found in the fuel
system or if the fuel tank needs to be
cleaned, have a Yamaha dealer service the
watercraft.
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EJU20150
Changing the engine oil
WARNING@ Engine oil is extremely hot immediately
after the engine is turned off. Coming
into contact with or getting any engine
oil on your clothes could result in burns.
@
CAUTION:@
Do not run the engine with too much or
not enough oil in the oil tank. Oil could
spray out or the engine could be dam-
aged.

Be sure to change the engine oil after
the first 10 hours of operation, and
every 100 hours thereafter or at the
start of a new season, otherwise the
engine will wear quickly.
The oil filter should be replaced every
two years or every 200 hours of opera-
tion. Have a Yamaha dealer replace the
oil filter if necessary.
@
It is recommended to have a Yamaha
dealer change the engine oil. However, if
you choose to change the oil on your own
consult a Yamaha dealer.
NOTE:@ Dispose of used oil according to local regu-
lations.
@
Recommended engine oil:
See page 3-3.
Oil quantity:
With oil filter replacement:
2.2 L (2.3 US qt, 1.9 Imp qt)
Without oil filter replacement:
2.0 L (2.1 US qt, 1.8 Imp qt)
Total amount:
4.3 L (4.5 US qt, 3.8 Imp qt)
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4-12
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CAUTION:@ If oil is leaking or the oil pressure warn-
ing indicator comes on when the engine
is running, immediately turn the engine
off and have a Yamaha dealer check the
watercraft. Continuing to operate the
engine under such conditions could
cause severe engine damage.
@
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EJU01819
Checking the air filter element
The air filter element should be checked
every 12 months or every 100 hours of oper-
ation.
To check the air filter:
1. Remove the rear and front seats. (See
pages 2-5 and 2-6 for seat removal and
installation procedures.)
2. Remove the air filter case cover
screws1, slide the locks 2 open, and
then remove the case cover.
3. Remove the air filter element and check
it for dirt and oil. Replace the air filter ele-
ment if there is any oil buildup, or every
2 years or every 200 hours of operation.
4. Install the air filter element in the air filter
case, and then install the case cover.
CAUTION:@
Make sure that the air filter element is
installed in the filter case properly.

Do not start the engine with the air fil-
ter element removed, otherwise the
pistons and cylinders could be dam-
aged.

If cleaning the air filter element, use
cold or lukewarm water and let it air
dry completely. Do not use detergent
or solvent to clean the air filter ele-
ment, or dry it with heat or com-
pressed air, otherwise it could be
damaged.
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4-16
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EJU18201
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 one spark plug shows a distinctly
different color, the engine could be defec-
tive. Do not attempt to diagnose any prob-
lems 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.
Removing a spark plug:
1. Remove the air filter case cover and air
filter element. (See page 4-13 for air filter
removal and installation procedures.)
2. Remove the spark plug.
Measure the spark plug gap a with a
wire thickness gauge. Replace the spark
plugs or adjust the gap to specification if
necessary.Specified spark plug: NGK CR9EB
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
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4-23
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EJU18231
Adjusting the fuel injection
system
The fuel injection system was set at the
Yamaha factory. Have a Yamaha dealer ser-
vice the watercraft if necessary.
CAUTION:@ Do not attempt to adjust the fuel injection
system. If the settings are changed poor
engine performance and damage may
result.
@
EJU01824
Checking the trolling speed
1. Put the watercraft in the water.
2. Start the engine and warm it up. Use the
tachometer in the multifunction meter to
check the trolling speed.
If the trolling speed is out of specification,
have a Yamaha dealer make this adjust-
ment.Trolling speed: 1,600–1,800 r/min
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4-25
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EJU01359
Specifications
MODEL
ITEMUnit FX140/FX Cruiser
WATERCRAFT CAPACITY
Maximum people on board Number of people 3
Maximum load capacity kg (lb) 240 (530)
DIMENSIONS
Length mm (in) 3,340 (131.5)
Width mm (in) 1,230 (48.4)
Height mm (in) 1,160 (45.7)
Dry weight kg (lb) 362 (798)
PERFORMANCE
Maximum output kW (PS) @ r/min 103.0 (140)@ 10,000
Maximum fuel consumption L/h (US gal/h, Imp gal/h) 44 (11.6, 9.7)
Cruising range at full throttle hr. 1.59
Trolling speed r/min 1,600–1,800
ENGINE
Engine type 4-stroke
Number of cylinders 4
Engine displacement
cm
3 (cu in)998 (60.9)
Bore & stroke mm (in) 74 ×
58 (2.91 ×
2.28)
Compression ratio 11.4:1
Lubrication system Dry sump
Cooling system Water cooled
Starting system Electric starter
Ignition system TCI
Spark plug CR9EB (NGK)
Spark plug gap mm (in) 0.7–0.8 (0.028–0.031)
Battery capacity V-AH 12-19
Charging system Flywheel magneto
UF1B71.book Page 25 Tuesday, November 12, 2002 4:17 PM