1967

In 1967, Yamaha brought in the RD05A from the beginning of the season, which is an improvement of the V4 powered RD05 with reduced weight. These were ridden by Phil Read and Bill Ivy. The title battle between M. Hailwood and Read lasted until the final round. Both riders had the same number of final points standing after the final round at 50 points. The title went to Hailwood as he had more race wins in the season (five wins for Hailwood against four wins for Read). Yamaha's Read and Ivy finished the ranking in second and third respectively, but Yamaha was not able to reclaim the manufacturer's title.

The opening round began favorably for Read. He took the lead while his rival Hailwood retired from the race in lap 14. Read won with a comfortable margin of 20 seconds over the second-place rider Ralph Bryans (Honda). The second round in West Germany saw a setback for Yamaha with a transmission issue for Ivy and a spark plug replacement for Read, which resulted in a 40 second lead for Honda's Bryans. Despite closing the gap by three seconds per lap, Read finished the race in 2nd.

Ivy and Read had a contrasting race in the third round in France. Hailwood was in the lead up to lap 14. However, the two Yamaha riders improved their pace later in the race to overtake the Honda rider. Ivy and Read went on to take a one-two finish, which coincidentally was the same result as in the 125cc class. Ivy was also able to achieve double class wins on the same day. The title race became more complicated from the 4th round onwards as Hailwood picked up his performance to win five times, while Read won three times and Ivy once. The title was still undecided after the 12th round, taking the championship race into the final round in Japan.

That final round saw Read retiring from the race in lap four due to engine failure. Hailwood, who was leading the race in the early stages was also forced to retire. The final stages of the race saw Yamaha's Hasegawa and Ivy at the front, but they encountered machine trouble too and were forced to retire from the race. This put Honda's Bryans in 1st position, and he then went on to win the race. Motohashi finished behind him in second. This result meant that Honda, which had won seven out of the 13 races, took the manufacturer's title. The points tally for Read and Hailwood was tied at 50 points, and the championship was handed to Hailwood for having the larger number of wins.

In 1967, Yamaha introduced a liquid-cooled, 2-stroke V4 powered RA31. Rivals included Suzuki, Bultaco and EMC. In the opening round in Spain, Suzuki took the lead at the start, but Phil Read and Bill Ivy fought back quickly to regain the lead within the first lap. The gap between 3rd and below increased gradually. After Ivy took over the lead from Read in lap two, the duo went on to finish one-two and make an auspicious start to the season. However, the next race in Hockenheim was a nightmare for the Yamaha duo. They were able to overtake the leading Suzuki riders in lap six, but Ivy was knocked out of contention by a rider who lost control of his bike as he was about to be lapped. Read was also unable to avoid the tangle, which resulted in a one-two finish for Suzuki.
They were able to regain control of the championship, however, from the third round in France. Read took the lead in lap two, and then in lap seven, Ivy took over to put the two Yamaha riders in front. Ivy stayed in front safely for the final eight laps to win the race, followed by Read. This great riding by Ivy and Read continued as Yamaha controlled the season campaign. Read took the win at the Isle of Man with Akiyasu Motohashi in third. This result ensured a third consecutive win in the Isle of Man TT in this class. Yamaha took its sixth win at the end of round seven in Czechoslovakia, with a possibility of clinching the championship in the 8th round in Finland. However, Suzuki took the win in Finland followed by Ivy in second place. In the following Ulster Grand Prix, Ivy finished in front to clinch the manufacturer's title for Yamaha. Ivy won again in the 10th round in Italy to give him the rider's championship. Ivy went on to win in Canada and Japan, with a total tally of 76 points and 56 effective points.