The XS Eleven was Yamaha's first four-cylinder four-stroke motorcycle, built from late 1977 to 1983. Its 1,101 cc DOHC four sits across a duplex cradle frame and drives through a five-speed with shaft drive. In the US the 1979 Standard was the F model, and that year Yamaha added the XS Eleven Special. You're looking at a 1979 Yamaha XS1100.