ENGINE

An engine () operable in a premixed combustion system and a diffusion combustion system. The engine () includes a main fuel injection valve (), a pilot fuel injection valve (), a liquid fuel tank (), a main fuel supply path (), a pilot fuel supply path (), a pilot fuel filter (), a pilot fuel high-pressure pump (), a pilot fuel tank (), and a pilot fuel supply pump (). The pilot fuel tank () stores pilot fuel sent from the pilot fuel high-pressure pump () and not injected by the pilot fuel injection valve (). This pilot fuel is sent to an automatic backwash filter () and a pilot fuel filter () while not passing through the liquid fuel tank ().