A portable engine-driven system comprising an engine, wherein the engine is configured to drive a generator, a fuel tank, and a high pressure fuel pump operatively coupled to the engine and the fuel tank. The high pressure fuel pump may be positioned within the fuel tank and configured to pump fuel from the fuel tank to the engine. A check valve and a fuel pressure regulator may be positioned in line between the high pressure fuel pump and the engine, wherein the pressure regulator is configured to regulate a pressure of the fuel between the high pressure fuel pump and the engine. The pressure regulator may be positioned within the fuel tank.
