Mercury - NGK LFR4A-E Standard Spark Plug Ignition Series Nickel Alloy 8M0157328. Overview. There's something reassuring about the instant snap of a clean ignition. It's that moment when you turn the key, hear the engine catch, and feel the whole boat come alive beneath you. A good spark plug is a small part of that moment, but any boater who's spent enough time on the water knows how much depends on it. The Mercury Marine part 8M0157328 NGK LFR4A-E Spark Plug is one of those little essentials t