The 420BU is a propane powered, ultra-high speed burnisher that gives floor care professionals the options they want to customize a machine to their needs. Based on the decades popular Mean Machine™, the 420BU is available in four different widths – 21, 24, 28, & 40 inches. Each model comes standard with a 12-volt on board electric starter and clutch. A passive vacuum and EcoSense emissions monitoring system are optional at extra charge (active vacuum is standard on the 40″ model). Powered by an 18-HP, 603 cc Kawasaki engine, the 420BU uses 34 percent less fuel and requires 40 percent fewer oil changes than other machines in its class.