1979

In 1979, Frenchman Christian Sarron joined the Yamaha team alongside defending champion Kenny Roberts and Johnny Cecotto, who had finished 3rd in the previous year's ranking. The latest machine, the YZR500 (OW45) was introduced with further refinements in a bid to take a second consecutive title this year. The majority of the 500cc class participants this year were on Suzuki's 4-cylinder machine, but Roberts made a big turnaround towards the end of the series on the Yamaha to win his second consecutive championship title. However, the manufacturer's title went to Suzuki.

After injuring himself during pre-season testing in Japan, Roberts sat out the first round of the '79 series in Venezuela. This opening round was won by Barry Sheene (Suzuki). The rest of the top places were dominated by Suzuki riders as well. Sarron in 7th place was Yamaha's top finisher in this race. Roberts returned for the second round in Austria and won the race. Then he went on to win the fourth and fifth rounds in Imola and Spain respectively. Roberts also won the Yugoslavian GP, which was now held in Rijeka. This put him in the lead in the season ranking. Less than satisfactory performances later in the season, however, handed the top ranking position to Virginio Ferrari (Suzuki).

Roberts returned to the top of the ranking by finishing 4th in the ninth round of the season in Sweden. In the eleventh round at Silverstone he got his fifth win of the series. But the title race would not be decided until the final round. . In the final race at Le Mans, Ferrari crashed out of the race, while Roberts finished third to clinch the championship. Sarron collected points in seven out of the 11 races to finish 11th in the ranking. The YZR500 development rider, Ikujiro Takai, participated in the Swedish GP and finish 8th. Honda's two 4-stroke machines entered this race, but both dropped out mid-race.

The third year of the Formula 750 was run as a 10-round series (two heats per round, a total of 20 heats). Patrick Pons on the Yamaha TZ750 succeeded in winning his first title this season. He became the first Frenchman to be crowned a road race world champion. After taking the top spot in the championship ranking away from Cecotto (YZR750) at the US round, Pons won both heats in West Germany. In the final round in Rijeka, he finished both heats in third to clinch the title. This gave Yamaha its third consecutive title. The Formula 750 World Championship came to a close this year.