2002 YAMAHA GP1200 service

4-14
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EJU01106
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: BR8ES-11
Spark plug gap:
1.0–1.1 mm (0.039–0.043 in)
Spark plug torque:
25 N·m (2.5 kgf·m, 18 ft·lb)
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EJU01116
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.
EJU01117
Troubleshooting chart
TBC-F0X7ETROUBLE POSSIBLE CAUSE REMEDY PAGE
Engine does not
startStarter motor does not turn over
Engine shut-
off switchClip not in place Install clip
2-8
Fuse Burned out Replace the fuse and
check wiring4-21
Battery Run down Recharge 4-19
Poor terminal connec-
tionsTighten as required
4-19
Terminal corroded Clean—
Starter motor Faulty Have serviced by
Yamaha dealer—
Micro-com-
puterOverheat mode Cool down engine
2-13
Starter motor turns over
Fuel cock Turned to “OFF”Turn the fuel cock to
“ON”2-7
Fuel Empty Refill as soon as possi-
ble3-3
Stale or contaminated Have serviced by
Yamaha dealer4-9
Fuel tank Water or dirt present Have serviced by
Yamaha dealer4-10
Spark plug Fouled or defective Clean or replace 4-14
Spark plug cap Not connected or loose Connect properly 4-14
Crankcase Filled with water Crank engine with plug
out until clean5-8
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer4-10
Choke Choke valve can not be
closed surely by lever
operationHave serviced by
Yamaha dealer—
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Engine runs irregu-
larly or stallsFuel Empty Refill as soon as possi-
ble3-3
Stale or contaminated Have serviced by
Yamaha dealer4-9
Choke Lever is moved to on Move back to original
position2-8
Fuel filter Clogged or water
pooledHave serviced by
Yamaha dealer4-10
Fuel tank Water or dirt present Have serviced by
Yamaha dealer4-10
Spark plug Fouled or defective Replace 4-14
Incorrect heat range Replace 4-14
Gap incorrect Adjust 4-14
Spark plug cap Loose Connect properly 4-14
Cracked, torn, or dam-
agedHave serviced by
Yamaha dealer—
Electrical wir-
ingLoose connection Tighten or connect
properly—
Carburetor Incorrect idle adjust-
mentAdjust idle
4-20
Clogged Have serviced by
Yamaha dealer—
Warning light or
indicator blinksFuel level Empty Refill as soon as possi-
ble3-3
Engine oil level Empty Refill immediately 3-4
Oil filter clogged Clean 4-11
Engine over-
heatedJet intake clogged Clean 5-4
Water temperature
sensor is failedHave serviced by
Yamaha dealer2-13
Low battery
voltageBattery voltage low Charge 4-19
Battery terminal con-
nected wrongConnect properly
4-19 TROUBLE POSSIBLE CAUSE REMEDY PAGE
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Wate rcr af t slow or
loses powerCavitation Jet intake clogged Clean 5-4
Impeller damaged or
wornHave serviced by
Yamaha dealer—
Engine over-
heatedJet intake clogged Clean
5-4
Fuel filter Clogged Have serviced by
Yamaha dealer4-10
Spark plug Fouled or defective Replace 4-14
Incorrect heat range Replace 4-14
Gap incorrect Adjust 4-14
Spark plug
capsLoose Connect properly
4-14
Electrical wir-
ingLoose connection Tighten or connect
properly—
Fuel Stale or contaminated Have serviced by
Yamaha dealer4-9
Bilge Water in bilge Drain 3-7 TROUBLE POSSIBLE CAUSE REMEDY PAGE
UF0X72.book Page 3 Friday, August 3, 2001 11:13 AM