Cleaning And Adjusting The Spark Plugs - Yamaha FX High Output WaveRunner 2007 Owner's/Operator's Manual

EJU34381
Cleaning and adjusting the spark
plugs
The spark plug is an important engine compo-
nent and is easy to inspect. The condition of
the spark plug can indicate something about
the condition of the engine. For example, if
one spark plug has a distinctly different color,
the engine could require servicing. Do not at-
tempt to diagnose any problems yourself.
Have a Yamaha dealer service the watercraft.
Remove and inspect the spark plugs periodi-
cally; heat and deposits will cause the spark
plugs to slowly break down and erode. If elec-
trode erosion becomes excessive, or if carbon
and other deposits are excessive, replace the
spark plug with the specified plug.
Specified spark plug:
CR9EB
To remove a spark plug:
(1) Remove the air filter case cover and air
filter element. (See page 88 for air filter
element removal and installation proce-
dures.)
(2) Remove the spark plug cap.
ECJ00210
CAUTION:
Do not use any tools to remove or install
the spark plug cap, otherwise the ignition
coil coupler could be damaged. The spark
plug cap may be difficult to remove be-
cause the rubber seal on the end of the
cap fits tightly. To remove the spark plug
cap, simply twist it back and forth while
pulling it up; to install it, twist it back and
forth while pushing it down.
(3) Remove the spark plug.
Measure the spark plug gap with a wire
thickness gauge. Replace the spark plug
Maintenance and care
or adjust the gap to specification if neces-
sary.
1 Spark plug gap
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
To install a 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.
Spark plug tightening torque:
12.5 Nm (9.2 ft-lb) (1.27 kgf-m)
(4) Install the spark plug cap.
NOTE:
Wipe off any water on the spark plug or in-
G
side the spark plug cap before installing the
cap. Push the spark plug cap down until it is
securely installed.
If a torque wrench is not available when you
G
are installing a spark plug, a good estimate
of the correct torque is 1/4 turn to 1/2 turn
past finger tight using the spark plug
wrench included in the tool kit. Have the
spark plug adjusted to the correct torque
with a torque wrench as soon as possible.
90