MAINTENANCE & CARE 4
SPARK PLUG CLEANING AND ADJUSTMENT
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 explosion.
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 has a distinctly different color, the engine could require servicing. Do not attempt to diagnose any problems yourself.
Have a Yamaha dealer service the boat. Remove and inspect the spark plugs periodically; heat and deposits will cause the spark plugs 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: CR9EB
1 Spark plug gap
To remove a spark plug:1)Remove the air filter case cover and air filter element. (See page
2)Remove the spark plug cap.
NOTICE: Do not use any tools to remove or install the spark plug cap, otherwise the ignition coil
coupler could be damaged. The spark plug cap may be difficult to remove because the rubber seal on the end of the cap fits tightly. To remove the spark plug cap, simply twist it back and forth while pulling it up; to install it, twist it back and forth while pushing it down.
3)Remove the spark plug. Measure the spark plug gap with a wire thick- ness gauge. Replace the spark plug or adjust the gap to specification if necessary.
Spark plug gap:
0.7~0.8mm (0.028~0.031 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
12.5Nm (9.2
4)Wipe off any water on the spark plug or inside the spark plug cap, and then install the cap. Push the spark plug cap down until it is securely installed.