99101-ZG0-0580 Main (#58) Jet - Overview. The 99101-ZG0-0580 Main (#58) Jet is a critical component of Honda marine engine fuel systems. This OEM main jet controls the precise flow of fuel to the carburetor, ensuring the correct air-fuel mixture for optimal engine combustion and performance. It supports the fuel delivery system by contributing to seamless fuel flow regulation, reliability, and consistent engine operation. Manufactured to meet Honda's strict factory standards, it ensures seamless