The KFX450R is a favorite of the Monster Energy Monster Army with its 449cc liquid-cooled, four-stroke single that boast a dual overhead cam (DOHC). The KFX engine features four valves per cylinder that really cranks up the performance to impressive highs for the power hungry quad racers. The induction system features a 32-bit digital fuel injection system with a whopping 42mm throttle body. The highly-rigid aluminum frame contributes to the excellent handling and traction the KFX450R known for. The MSRP of the KFX450R reigns in at just over $7,000.