16735-ZY3-004 Fuel Pump Unit - Overview. The 16735-ZY3-004 Fuel Pump Unit is a critical component within Honda marine engine systems. This fuel pump unit supports the fuel delivery system by ensuring a consistent flow and proper pressure of fuel from the tank to the engine's combustion system. Its role is essential to maintain efficient engine operation and reliable performance under varying marine conditions. Designed and manufactured to meet exact Honda factory specifications, the 16735-ZY3-00