Maintenance64EMU28941GreasingYamaha grease A (water resistant grease)Yamaha grease D (corrosion resistant grease; for propeller shaft)F30A, F40BEMU28955Cleaning and adjusting spark plugThe spark plug is an important engine com-ponent and is easy to inspect. The conditionof the spark plug can indicate somethingabout the condition of the engine. For exam-ple, if the center electrode porcelain is verywhite, this could indicate an intake air leak orcarburetion problem in that cylinder. Do notattempt to diagnose any problems yourself.Instead, take the outboard motor to aYamaha dealer. You should periodically re-move and inspect the spark plug becauseheat and deposits will cause the spark plugto slowly break down and erode. If electrodeerosion becomes excessive, or if carbon andother deposits are excessive, you should re-place the spark plug with another of the cor-rect type.1. Remove the spark plug caps from thespark plugs.2. Remove the spark plug. If electrode ero-sion becomes excessive, or if carbonand other deposits are excessive, youshould replace the spark plug with an-other of the correct type. WARNING!When removing or installing a sparkplug, be careful not to damage the in-sulator. A damaged insulator couldallow external sparks, which couldZMU04081
