Super Clean FAT BOY! In 2004, the American motorcycle manufacturer launched the Harley-Davidson Fat Boy, a classically styled cruiser that received several modifications over its production time, including the 2000 model year that came with a larger displacement engine. For the 2004 model year, the bike was fitted with a new long-lasting taillight, an effortless clutch, more durable brake pads, new engine seals, and chrome-plated head bolts. The bike's power was the same as previous models, coming from a 1,450cc four-stroke V-twin air-cooled engine, which in some countries was delivered with a fuel injection system, boasting 67 hp at 5,200 rpm and 117 Nm (86 lb-ft) torque at 3,500 rpm.