Like its rivals Honda, Aprilia, Ducati, and KTM, the Japanese manufacturer will be focusing entirely on the new V4 concept. Suzuki won the MotoGP World Championship in 2020 with a straight-four engine (with Joan Mir), and Yamaha followed suit a year later with Fabio Quartararo.
Since the Emilia Romagna GP in September 2024, we've known that Yamaha had a V4 engine on the test bench.
So it took almost five years for the collaboration between Yamaha and Engineer Luca Marmorini from Marmotors to reach visible results. And nobody seems to remembers that Yamaha once used three different 500cc engine concepts within three years: straight-line, square-four, and V4 engines.
Because Monster Yamaha Team Manager Massimo Meregalli mentioned - after the team's presentation for 2023 in Jakarta - that the work of Italian Engine Engineer Luca Marmorini (hired by Yamaha in spring 2022) would only really come to light in 2024, there was speculation as to whether the former Formula 1 technician from Toyota and Ferrari might be planning and developing a V4 MotoGP engine like those used by its rivals Ducati, Honda, Aprilia, and KTM. Only Suzuki has pursued a straight-line engine concept with the GSX-RR, like Yamaha did with the YZR-M1. Suzuki buried the 800cc V4 engines of the GSV-R after the 2011 season, due to a chronic lack of success.
However, no one at Yamaha wanted to confirm the presumed construction of a 1000cc V4 MotoGP engine until September 2024. Reference was always made to the discussions between the manufacturers who had already defined the technical regulations from 2027 to 2031 in the MSMA this year. The displacement will then be reduced to 850 cc and the maximum bore from 71 to 75 mm.
In the past, managers at Yamaha have often indicated that it wouldn't be expedient to build a V4 before 2027. One reason for this was because the Japanese manufacturer has been selling straight-line four SuperSport bikes, like the successful R6 and R1, for decades. Straight-line engine concepts have been part of Yamaha's DNA for ages.
However, we assume that Fabio Quartararo was already privy to the new V4 concept when he signed a new Yamaha contract for 2025 and 2026 in April 2024, for a reported €12 million Euros per year.
Fabio Quartararo had already run out of patience in Assen in 2023, for example, when he suffered a serious injury in a crash on Sunday (after finishing third in the Sprint). In 2022, he was already struggling unsuccessfully against the fast and superior Ducati Desmosedici with the underperforming M1 Yamaha.
1981: Square Four, only one season for the official team
Only some older (or experienced) MotoGP fans remember how quickly Yamaha came up with one new engine concept after another in the good old two- stroke 500 cc era.
Kenny Roberts won the World Championship three times in a row, from 1978 to 1980, with a straight-line four-cylinder. In response to Suzuki's tireless efforts, Yamaha launched the first YZR500 with a straight-line engine and aluminum frame (OW48) in 1980, which was soon replaced by the slightly modified OW48R.
In 1981, official riders Roberts and Sheene were given a new official Yamaha with a 500cc square-four engine (an engine with four cylinders arranged in a square) for the first time. The code name of this YZR500 was OW54. However, Yamaha's new square-four concept still had its pitfalls in 1981. "Kenny's new square-four Yamaha broke down right at the start in Austria. I won with the Suzuki. I was then running for the world championship and fought for the title against that damn Lucchinelli," Randy Mamola said, describing the 1981 500 cc World Championship season in an interview with GPone.com.
While Suzuki aces Marco Lucchinelli and Randy Mamola secured a one-two victory in the 1981 500cc World Championship, the Yamaha engineers went back to the drawing board. The OW54 was suffering from mechanical problems, plus Kenny Roberts had to miss a few races for health reasons.
A promising new 500cc V4 engine was developed in record time for 1982, with which Yamaha won the 500cc World Championship in 1984, 1986, and 1988 thanks to "Steady Eddie" Lawson, and Wayne Rainey won three more titles in a row from 1990 to 1992.
This V4 Yamaha made its debut in 1982 at the second race of the season at the ultrafast Salzburgring in the Austrian GP. However, the radical change with the V4 only benefited the Yamaha factory team with Roberts and Sheene. All the other Yamaha 500 cc teams had to make do with the further developed YZR500, which had then been code-named OW60 and was powered by the 1981 square-four engine.
With this OW60, Roberts and Sheene secured a one-two victory at the season opener in Buenos Aires, before the official V4 entered the scene in the Yamaha tent in Salzburg, which made a name for itself as the OW61. It was the first 500cc two-stroke GP bike from Japan with a V4 engine. Suzuki adopted this promising concept about five years later for Kevin Schwantz.
Yamaha took an unconventional and courageous approach at the time. Since the V4 had two crankshafts, the front cylinders weren't optimally cooled, the frame had to manage without reinforcements underneath the engine, and the rear suspension was mounted horizontally.
In this new OW61 with the V4 power engine, the magnesium casing on both motorcycles broke at the Finnish GP on the street circuit in Imatra. The light metal couldn't withstand the stress of the bumpy when crossing the track after the first corner. "The Yamaha engineers are careless," Roberts had said jokingly. "Because they built a test track in Japan without a railroad crossing."
Roberts often drove the Yamaha engineers to despair with his pithy remarks. After a 5th place at the French GP in Le Castellet in 1981 on the new square-four Yamaha, the Yamaha technicians were curious to hear what the American had to say.
"This bike is a rocket," King Kenny had said. But the happy faces of the Japanese darkened after the next sentence. "But we need a racetrack without corners," he added, laconically.
Roberts finished the 1982 season in 4th place, overall. New Zealander Graeme Crosby, from Giacomo Agostini's Marlboro Yamaha team, on the other hand, remained loyal to the then mature OW60 and finished runner-up in the World Championship.
Even though Yamaha lost the title that year, the OW61 represented an important turning point and formed the basis for many further successes in the premier class.
1983: Yamaha lost the World Championship by 2 points
In 1983, the new V4 factory Yamaha was equipped with an even more powerful and compact engine, the OW70 model, which now also featured an aluminum Deltabox chassis.
Kenny Roberts fought a fierce World Championship battle with the V4 Yamaha against his fellow countryman, Freddie Spencer, on the new V3 three-cylinder two-stroke Honda in 1983, with "Fast Freddie" winning by 144 to 142 points.
Roberts' American protégé, Eddie Lawson, ousted Sheene from the official Yamaha team in 1983. He ended the season in 4th place behind Spencer, Roberts, and Mamola and went on to win three World Championship titles with the V4 Yamaha.
Sheene returned to a private Suzuki after three years with Yamaha years and plummeted to 14th place in the World Championship.
Randy Mamola: "I'm not a historian"
After more than 40 years, truthfully reconstructing the events of that time isn't so easy. Even the Australian Kel Carruthers - 250cc World Champion on a Benelli in 1969, who then discovered Kenny Roberts, his team manager and crew chief in the 500cc World Championship with Yamaha, in the States, and is now almost 88 years old on January 3rd - doesn't remember everything. However, he promised to check the facts in some old books.
The legendary Mike Sinclair, renowned chief mechanic in the Suzuki and Yamaha factory teams for many years, was also unable to provide any clarification. "Back then, I worked for Wil Hartog in the Suzuki factory team. He finished ninth at the start of the season in Austria and, then, surprisingly ended his career a week later at the second Grand Prix in Hockenheim," Sinclair recalled. "I became unemployed as a result and moved to England, where my wife gave birth to our first child."
Even our sprightly interviewee Randy Mamola (66), for example, couldn't remember the square-four engine that the Yamaha 500 factory team used for at least one season in 1981 between the straight-line engine of 1980 and the V4 engine of 1982. "I'm not a historian," the popular Californian said, laughing. He was runner-up in the 500cc World Championship four times and celebrated 13 GP victories on Suzuki, Honda, and Yamaha but never became world champion.
Photo: Kenny Roberts on his Yamaha YZR500 0W48 courtesy of MotoAmerica by Brian J. Nelson.