1965

In 1965, Phil Read and Mike Duff won seven races and one race respectively out of the 13 races of the GP series to give Yamaha its second manufacturer's title in the row. Read also took the rider's championship, while Duff finished second in the ranking. The title was decided by total points scored by a rider in his best seven finishes of the series, which represented the smallest majority of the 13 races. Eight points were allocated to 1st place finishes, followed by 6, 4, 3, 2 and 1 points allocation respectively down to 6th place.

Yamaha started the season on a high note, with Read and Duff taking a one-two finish in Daytona in the USA. They carried this momentum through to the European rounds and took another one-two finish in the second round in West Germany. The race was held on the treacherous South Circuit of Nurburgring instead of the North Circuit. A total of 44 machines lined up on the grid, and the factory machines in this event included Suzuki (liquid-cooled, 2-stroke, 4-cylinder), MZ (liquid-cooled, 2-stroke, 2-cylinder), Bultaco (air-cooled, 2-stroke, single-cylinder), Aermacchi (air-cooled, 4-stroke, single-cylinder), as well as Yamaha (air-cooled 2-stroke, 2 cylinder) and Honda (air-cooled 4-stroke, 6-cylinder). Honda's Redman could not start the race due to injuries incurred in the 350cc race the previous day. The race was dominated by the two Yamaha riders, lapping everyone except the third placed man, Ramon Torras (Bultaco). Yamaha achieved a one-two finish in what could be described as a survival race, with only 22 riders crossing the finish line and only 10 classified as finishes.

Read on Yamaha took charge of the Spanish, French, the Netherlands, and Czechoslovakia GP's to take six wins. His rival Redman took wins in the Isle of Man, Belgium GP and in the East German GP. The 10th round was the decider in bringing Yamaha its second consecutive manufacturer's title. The race was held in Dundrod of North Ireland. Read and Duff once again took a one-two finish in pouring rain to clinch the consecutive manufacturer's title with three races still remaining. Read also took the rider's championship this year. For two years in a row, Yamaha took away both the rider's and manufacturer's championship.

In 1965, Yamaha took its first GP125cc class win in the Isle of Man race. Yamaha originally began competing in the GP with the Isle of Man in its sights, however, Yamaha was unable to match the pace of Honda and Suzuki in this class. Riding a machine powered by a 2-cylinder engine with a more competitive liquid cooling system, P. Read took the checkered flag in front. It was the first win for Yamaha in the GP125cc class. The machine was the liquid-cooled version of the RA97, which debuted in the Netherlands the previous year to finish 2nd. In the Netherlands GP which followed, Duff took the win, which increased Yamaha's number of wins to two, and brought Yamaha to 4th overall in the season ranking.