Champion RV12YC Copper Plus Marine Spark Plug Champion marine spark plugs are quality OEM replacements. The Champion RV12YC Spark Plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. These marine spark plugs are designed to resist overheating under heavy engine loads. Copper Plus for dependable performance Copper core electrode allows for accurate control of heat range for longer life Patented TinTac and ULTRASEAL coated shell for max