The Yamaha XJ600 was a motorcycle manufacture by Yamaha. It is a relatively light motorcycle with top half fairing and around 72 hp/54 kilowatts. The XJ600 was built from 1984 until 1991, when it was replaced with the Yamaha Diversion/Seca II. In North America, the bike was sold as the FJ600. The 1984 Yamaha XJ600/FJ600 is notable for being the first Japanese inline-4 with a displacement of 600cc . The XJ was also one of the first bikes inline-4s to use mono-shock rear suspension design.