2B4115 Push/Choke Key (2B) - Overview. The 2B4115 Push/Choke Key (2B) is a critical component for Honda marine engine ignition systems. Designed to operate both the push-to-start and choke functions, this key supports the engine starting and control system, playing a vital role in the reliable operation of your Honda marine engine. Engineered to fit precisely with existing components and maintain factory standards, it ensures seamless integration with existing parts, maintaining optimal performa