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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 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 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.

Standard spark plug: BR8ES-11

Measure the spark plug gap a with a wire thickness gauge before installing the spark plug. Adjust the gap to specification if necessary.

Spark plug gap:

1.0–1.1 mm (0.039–0.043 in)

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.

Spark plug torque:

25 N·m (2.5 kgf·m, 18 ft·lb)

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