Yamaha AR210, Owner'S Manual

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4-7
M
AINTENANCE
& C
ARE
4
SPARK PLUG CLEANING AND
ADJUSTMENT
The spark plug is an important engine
component 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 elec-
trode porcelain is very white, this could
indicate an intake air leak or carbure-
tion problem in that cylinder.
Do not attempt to diagnose any prob-
lems yourself. Instead, take the boat to
a Yamaha Boat dealer. You should peri-
odically remove and inspect the spark
plug because 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, you
should replace the spark plug with
another of the correct type.
Before installing the spark plug, mea-
sure the electrode gap with a wire
thickness gauge; adjust the gap to
specification if necessary.
When fitting the plug, always clean the
gasket surface and use a new gasket.
Wipe off any dirt from the threads and
screw in the spark plug to the correct
torque.
NOTE: Before installing the spark plug
cap, be sure to wipe off any water on
the spark plug or inside the cap. Push
the spark plug cap down until it clicks.
NOTE: If a torque-wrench is not avail-
able when you are fitting a spark plug,
a good estimate of the correct torque
(with a new gasket) is 1/4 to 1/2 turn
past finger-tight. Have the spark plug
adjusted to the correct torque as soon
as possible with a torque wrench.
When removing or installing a spark
plug, be careful not to damage the
insulator. A damaged insulator could
allow external sparks, which could
lead to explosion or fire.
Standard spark plug:
NGK CR9EB
Spark plug gap: 0.7~0.8mm
(0.028~0.031 in)
Spark plug torque:
12.5 Nm (1.25 m-kg, 9 ft-lb)
WARNING