9807B-5615W S/PLG (SKJ20DR-M11) - Overview. The 9807B-5615W S/PLG (SKJ20DR-M11) is a genuine Honda spark plug designed to optimize the ignition system in Honda marine engine systems and select automotive engines. This critical component plays a key role in igniting the fuel-air mixture, ensuring smooth engine running and efficient combustion. Engineered as an OEM part, it guarantees flawless compatibility and long-lasting performance.. Key Features. High-quality spark plug designed to match Hond