To improve fuel injection accuracy.

A fuel injection servo valve 20 is arranged for each of two or more cylinders 4 of a marine engine 2 and regulates the amount of fuel injected into the cylinder 4. Valve control units 22 respectively control the servo valves 20. An engine control unit 24 transmits instructions to the valve control units 22. Operating devices 26a, 26b transmit the instructed number of revolutions to the engine control unit 24. Sensors 28, 30, 32 detect and transmit the number of revolutions of an engine 2 to the engine control unit 24. Each valve control unit 22 is arranged for every servo valve 20, and integrally assembled with the servo valve 20 for which the valve control unit 22 is arranged.