Mercury - 100 Hour Maintenance Kit FourStroke Series Premium Components 8M0097854. Overview. Any boater who puts long hours on the water knows the importance of routine maintenance. It is the kind of habit that pays you back every time your engine fires on the first turn and settles into that smooth, steady rumble you trust. The Mercury 8M0097854 100 Hour Maintenance Kit delivers that kind of confidence. It keeps your 2.1-liter Mercury FourStroke running clean, cool, and dependable-whether you a