Champion D9 Marine Spark Plug The Champion D9 Marine Spark Plugs are backed by global engineering from Federal-Mogul. These spark plugs have precious metals, FISS, and Hot Lock designs that provide a plug that withstands today's high-temperature, high-load service environments. Designed for high compression and aggressive environments; Manufactured for long-lasting durability; Backed by global engineering from Federal-Mogul; Superior performance and long lasting durability; Champion Spark Plugs # 509Application: Evinrude; 18mm Heads. Standard ignition; Johnson; 18 mm Heads. Standard ignition;