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EJU18201

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 one spark plug shows a distinctly different color, the engine could be defec- tive. 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.

Removing a spark plug:

1.Remove the air filter case cover and air filter element. (See page 4-13 for air filter removal and installation procedures.)

2.Remove the spark plug.

Specified spark plug: NGK CR9EB

Measure the spark plug gap a with a wire thickness gauge. Replace the spark plugs or adjust the gap to specification if necessary.

Spark plug gap:

0.7–0.8 mm (0.028–0.031 in)

4-15