Since the second Emilia Romagna GP, we have known that Yamaha had a V4 engine on the test bench. So it took more than three years for the collaboration between Yamaha and engineer Luca Marmorini from Marmotors to bear visible fruit. And nobody remembers that Yamaha once used three different 500cc engine concepts in three years: in-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 (he was 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 rivals Ducati, Honda, Aprilia and KTM. Only Suzuki has pursued an in-line engine concept with the GSX-RR, as Yamaha did with the YZR-M1. Suzuki buried the 800cc V4 engines of the GSV-R after the 2011 season due to 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 for 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.
Up to now, the Yamaha managers have often indicated that it would not be expedient to build a V4 before 2027. But 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 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 works team
Only the older GP fans remember how quickly Yamaha came up with one new engine concept after another in the good old 500cc era.
Kenny Roberts won the World Championship three times in a row from 1978 to 1980 with an in-line four-cylinder. In response to Suzuki's tireless efforts, Yamaha launched the first YZR500 with an in-line engine and aluminum frame (OW48) in 1980, which was soon replaced by the slightly modified OW48R.
In 1981, works riders Roberts and Sheene were given a new works Yamaha with a 500cc square-four engine, i.e. 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, was then on course for the world championship and fought for the title against damn Lucchinelli,”
Randy Mamola describes the 1981 half-liter world championship season.
As 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 ultra fast Salzburgring, the Austrian GP. However, the radical change with the V4 only benefited the works team with Roberts and Sheene; all other Yamaha 500 teams had to make do with the further developed YZR500, which was now codenamed OW60 and was powered by the Square Four plant from 1981.
With this OW60, Roberts and Sheene secured a one-two victory at the season opener in Buenos Aires, before the V4 works machine was rolled into the Yamaha tent in Salzburg, which made a name for itself as the OW61. It was the first 500cc two stroke GP machine from Japan with a V4 engine. Suzuki adopted this promising concept around five years later for Kevin Schwantz.
Yamaha took an unconventional and courageous approach at the time, as the V4 had two crankshafts, the front cylinders were not optimally cooled, the frame had to manage without reinforcement underneath the engine and the rear suspension was mounted horizontally.
In this new OW61 with the V4 power source, the magnesium housing on both motorcycles broke at the Finnish GP on the street circuit in Imatra. The light metal could not withstand the stresses of the bumpy track crossing after the first corner in the long term. “The Yamaha engineers are careless,” Roberts joked. “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 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,” said King Kenny. The happy faces of the Japanese only darkened after the next sentence. “But we need a racetrack without bends,” he added laconically.
Roberts finished the 1982 season in fourth place overall. New Zealander Graeme Crosby from Giacomo Agostini's Marlboro Yamaha team, on the other hand, remained loyal to the now 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 compatriot Freddie Spencer on the new V3 three-cylinder two-stroke Honda in 1983, with “Fast Freddie” winning by 144 to 142 points.
The American Roberts protégé Eddie Lawson ousted Sheene from the Yamaha works team in 1983. He finished the season in fourth place behind Spencer, Roberts and Mamola and went on to win four world titles with the V4 Yamaha.
Sheene returned to a private Suzuki after three Yamaha years - and plummeted to 14th place in the world championship.
Randy Mamola: “I'm not a historian”
After 40 years, it's not so easy to reconstruct the events of that time truthfully.
Even the Australian Kel Carruthers, 250cc World Champion on Benelli in 1969, then in America the discoverer of Kenny Roberts and his team manager and chief technician in the 500cc World Championship at Yamaha, now 80 years old, was left by his memory. However, he promised to look in 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 works team, who 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 looks back. “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 (64), for example, could not remember the square-four engine that the Yamaha 500 works team used for at least one season in 1981 between the in-line engine of 1980 and the V4 engine of 1982. “I'm not a historian,” laughed the popular Californian, who 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.