Quicksilver 33-862029 Spark Plug Ac Mr43LtsQuicksilver MR43LTS spark plugs come pre-gapped as specified by your engine manufacturer. Use only the spark plug listed in your engine owner's manual. Using the wrong plug can reduce optimum performance, reduce fuel economy or cause damage to your engine. Spark plugs are easy to change with common spark plug sockets.Application: Fits 2002-2016 MerCruiser 4.3L, 5.0L & 5.7L carbureted engines Made by AC Delco with nickel alloy tip, copper core and ribbed suppressor seal for durability and performance; Check your engine owner's manual for the correct spark plug and use only the plug as recommended by your engine's original equipment manufacturer; Don't just clean used spark plugs, replace them with new plugs for better performance;