16400-ZVT-003 Throttle Body - Overview. The 16400-ZVT-003 Throttle Body is a critical component in Honda marine engine systems. It supports the fuel injection and air intake system, playing a vital role in controlling the flow of air into the engine. This precision part ensures optimal engine power output and responsiveness, helping maintain your boat's operational reliability. Designed to meet strict factory specifications, it ensures seamless integration with existing parts, maintaining optima