16940-ZX2-003 Fuel Drain Petcock - Overview. The 16940-ZX2-003 Fuel Drain Petcock is an essential valve component designed to control the draining of fuel within Honda marine engine systems. It supports the fuel system by allowing maintenance technicians to drain fuel efficiently and safely from the engine, ensuring smooth operation and reliable performance. Made to OEM specifications, this petcock offers precise fitment and dependable functionality, integrating seamlessly with Honda marine rigg