Abstract: Systems, methods, and assemblies for providing improved fuel management to fuel injected engine systems of off-road vehicles, such as snowmobiles, personal watercraft, motorcycles, utility vehicles, and all-terrain vehicles. The fuel-injected engine systems can return fuel after passing through a pressure regulator located either upstream or downstream of the engine. Fuel may be returned to the fuel pump through various routes, rather than simply returning the fuel into the fuel of the fuel tank. Fuel may be returned directly to the fuel pump upstream of all fuel pickups or upstream of some fuel pickups and downstream from other fuel pickups. Some embodiments include a vapor separator located downstream of the pressure regulator but somewhere upstream of the fuel pump.