Prior to the transition to four stroke engines in 2002, the 500cc 2-stroke class was the top of the food chain in the Grand Prix Motorcycle World Championships. MV Agusta won 17 consecutive 500cc World Championships, from 1958 to 1974. All but 3 of those championships came from riders John Surtees, Mike Hailwood, and the prolific Giacomo Agostini.
By 1975, the two strokes were becoming the technology of choice. The Japanese were advancing the technology rapidly. Agostini fled to Yamaha, and brought them a Championship that year, but Suzuki was gaining. Years earlier they had hired Ernst Degner from the East German motorcycle company MZ, who built quite powerful two-stroke engines. Suzuki went on to with the 1976 and 1977 World Championships.
Very late in the 1977 season, Yamaha decided to try something different.