99101-124-0720 Main (#72) Jet - Overview. The 99101-124-0720 Main (#72) Jet is a critical component of the fuel system within Honda marine engine systems. It functions as the main carburetor jet, regulating the flow of fuel into the carburetor to ensure the proper air-fuel mixture is maintained, particularly at higher throttle settings. This part plays a vital role in keeping your marine engine running smoothly and reliably by ensuring fuel is delivered precisely as required, which supports opti