Cleaning And Adjusting The Spark Plugs - Yamaha SUPERJET 2007 Owner's/Operator's Manual

(2) Adjust the free play by loosening the lock-
nut and turning the adjuster.
1 Locknut
2 Adjuster
3 Throttle lever free play
Throttle lever free play:
7.0–10.0 mm (0.28–0.39 in)
EJU34371
Cleaning and adjusting the spark
plugs
EWJ00350
WARNING
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.
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 the
center electrode porcelain is very white, this
could indicate an intake air leak or carburetion
problem in that cylinder. Do not attempt to di-
agnose 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
Maintenance and care
and other deposits are excessive, replace the
spark plug with the specified plug.
Specified spark plug:
B7HS
Measure the spark plug gap with a wire thick-
ness gauge. Replace the spark plugs or ad-
just the gap to specification if necessary.
1 Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 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:
25.0 Nm (18.4 ft-lb) (2.55 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
60