TWO-STROKE THUNDER
Race historians will look at 1974 as a pivotal year in the ranks of 500cc World Championship Grand Prix road racing.
For 24 years straight, beginning in 1949 with the FIM’s (Federation Internationale Motocycliste) first World Championship, bikes using 4-stroke power dominated the 500cc class. Then, in 1974, Yamaha’s new OW23, with its inline 4-cylinder 2-stroke engine, won the FIM constructor’s title. The following year the OW23 carried 14-time World Champion Giacomo Agostini — he had never raced a 2-stroke motorcycle before signing with Yamaha — to his 15th and final world title. By 1976 Barry Sheene, riding Suzuki’s RG500 square-4 2-stroke, powered his way to consecutive world titles (1976-1977).
The Americans are coming
Two-stroke technology had methodically lodged itself into 500cc GP road racing, pushing 4-strokes out of the picture. And, come 1978, Grand Prix road racing was in for yet more change. The Americans were coming.
Indeed, and as we shall learn from Peter Starr’s podcast, , those brutish 2-stroke Grand Prix racers were tailored for Americans to compete in world championship competition. And as history shows us, the Yanks dominated the 500cc class for a string of 16 racing seasons, 1978 through 1993.
