9807B-5615P S/PLG (KJ20DR-M11) - Overview. The 9807B-5615P S/PLG (KJ20DR-M11) is a genuine Honda spark plug designed specifically for Honda marine engine systems. This spark plug plays a critical role in igniting the fuel-air mixture within the engine, ensuring reliable starts and efficient operation. Engineered to meet precise OEM specifications, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. OEM quality spark plug designed to