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EJU00552a

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 centre 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. Instead, take the water vehicle to a Yamaha Water Vehicle dealer. You should periodically 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.

a

KA0065

Standard spark plug:

BR-8ES

Before installing the spark-plug, measure the electrode gap with a wire thickness gauge; adjust the gap to specification if necessary.

Spark-plug gap: a

0.6~0.7 mm (0.024 ~ 0.028 in)

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.

Spark-plug torque:

25 Nm (2.5 m•kg, 18 ft•lb)

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 available when you are fitting a spark-plug, a good estimate of the correct torque (with a new gasket) is 1/4 to 1/2 a turn past finger- tight. Have the spark-plug adjusted to the correct torque as soon as possible with a torque wrench.

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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.

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