1963

In 1963, Yamaha competed again in the road race World GP after a year's break. The air-cooled, 2-cylinder, 2-stroke RD56 was the challenge machine for the season. Yamaha made four race starts this season in the Isle of Man, the Netherlands, Belgium, and Japan. Fumio Ito, who finished 6th in The Isle of Man TT 2 years earlier in Yamaha's first GP racing season, had his sights set on a higher finish this time. The race for the 250cc class prize on the Isle of Man TT unfolded with a breathtaking performance for Yamaha. The power of the Yamaha 2-stroke certainly stood out with a 2nd from Ito, and a 4th from Hiroshi Hasegawa. It was a first since World War II for a 2-stroke racer to place this high in the 250cc class at the TT race, and Ito's podium finish marked the first time a Japanese rider had stood on the podium at the TT.

The mostly flat 7.70 km circuit in the Netherlands had a slow-speed layout with a succession of curves of varying radiuses. The course also included some public road sections. There was much anticipation leading up to the race as to how Italy's Morini would take on Yamaha and Honda, and how Yamaha would be able to work around its 2-stroke weak point of engine brake effect. Great weather bought out in excess of 150,000 spectators for the event. First off the line was Ito, who took the early lead. Following hot on Ito's heels was Honda's James Redman, but the Morini rider Tarquinio Provini, winner of the 1st and 2nd races in succession, was not able to challenge Yamaha once throughout the entire race. The race turned out to be a battle between the Japanese machines, that is Ito versus Redman with the ending result matching that of The Isle of Man TT with Redman 1st followed by Ito 2nd. Yoshikazu Sunako followed up with another 4th-place finish.

In the following 5th round, the Belgium Grand Prix, Yamaha clinched its first GP victory at the Circuit de Spa-Francorchamps. The Benelli with its 4-cylinder engine made a blistering start but this was soon taken back by the Yamaha RD56. The order after the first lap was Yoshikazu Sunako in the lead followed by Ito, leaving the Benelli's 4-cylinder, the single-cylinder Morini, and the 4-cylindered Honda to follow. Apart from the change in the lead between Sunako and Ito in lap three, they completed nine laps with no threats from the third-place rider and below. Yamaha made its first win with a 1-2 finish in the last race of its three flyover rounds that year. Ito also broke the previous record for the race.

The modified version of the production model YA5 with its newly developed single-cylinder engine with rotary valve system was used for the 125cc class of the final GP of the season in Japan. Yoshikazu Sunako rode into 7th position, however, he was not able to gain any points for the effort.