99101-ZV5-1220 Main (#122) Jet - Overview. The 99101-ZV5-1220 Main (#122) Jet is a critical component in the fuel system of Honda marine engines. This main jet controls the flow of fuel within the carburetor, particularly at higher throttle settings, ensuring optimal combustion and engine performance. Manufactured to meet stringent factory specifications, it plays a vital role in maintaining smooth and efficient operation of Honda marine engines. Designed for seamless integration with existing p