PURPOSE: To control operations with fuel injection device of one engine freely switched over in such a way as to meet the requirements of two cycle or four cycle operations.

CONSTITUTION: A fuel discharging mechanism 7 equipped with a flow path valve 71 leading fuel to a flowout port 75 and with a solenoid 72 actuating the aforesaid valve, is disposed at a fuel flow path connecting a fuel injection pump 6 to an injection nozzle 3. In case of two cycle operations, fuel fed with pressure from the injection pump 6 every engine 1 revolution with no flow path valve actuated is supplied to a cylinder 2 by the injection nozzle 3. In case of four cycle operations, let fuel leak to the flow-out port 75 by the flow path valve 71 with the solenoid 72 controlled every two engine revolutions, so that fuel injection from the injection nozzle 3 is suspended.