For reciprocating engines, those units and components which deliver metered fuel and air to the engine. The fuel portion includes the carburetor, master control from the inlet side to the discharge nozzle(s), injection pumps, carburetor, injection nozzles and fuel primer.

对于活塞式发动机，向发动机输送计量燃油和空气的装置和部件。燃油部分包括化油器、从进气侧到排气喷口的主控、喷油泵、化油器、喷油嘴和启动喷油装置。

对于往复式发动机，向发动机输送燃料和燃气的装置和部件。燃料部分包括从出气侧到排气喷嘴、喷油泵、化油器、喷油嘴和燃油底火的化油器控制。

对于往复式发动机，向发动机输送燃料和空气的装置和部件。燃料部分不包括从进气侧到排气喷嘴、喷油泵、化油器、喷油嘴和燃油底火的化油器控制。