In 1981, British star Barry Sheene joined the factory Yamaha team. He had taken the 1976 and 1977 500cc titles with Suzuki and was considered a British racing hero. With him joining three-time champion Roberts on the team, it was a formidable lineup. The YZR500’s livery was also all-new for that year, changing from the Yamaha U.S. yellow/black livery that defined Roberts’ title threepeat to a white background with a flowing red block pattern on top with dark blue highlights around it. The two teammates sitting astride identical YZR500s gave off a brilliant aura of purebred Yamaha racing machinery.

Of the 11 rounds that year, Roberts won two while Sheene won one; the pair finished 3rd and 4th overall, respectively, and lost out on the title to Suzuki’s Marco Lucchinelli. However, the sight of the two of them racing in close proximity became a powerful symbol of Yamaha’s presence in GP racing.

That year, Yamaha introduced two versions of the YZR500. The 0W53’s engine had dual rear-exit exhausts and an aluminum frame, while the 0W54 used a square-four engine, in which the four cylinders are arranged alongside in pairs to form a square. It used a rotary disc valve intake system for an advantage at high speed. At the same time, Yamaha also developed a compact V4 engine to ensure the bike would not lose out on the straights, but as one engineer recalled, “It would have been risky to switch over to a V4 so suddenly, so we introduced the square-four unit as a kind of stop-gap measure.”

In 1982, Honda’s Freddie Spencer was racing the NS500 with its V3 engine and Kork Ballington was riding Kawasaki’s square-four KR500 that year, meaning each of the Big Four was running 2-stroke machinery in the premier class. Yamaha had entrusted its YZR500s to the aforementioned Roberts and Sheene, but also to Kiwi Graeme Crosby and Frenchman Marc Fontan. At the opening round in Argentina, Roberts and Sheene finished 1st and 2nd, respectively, getting the season off to an excellent start.

But what really captured fans’ attention was the next round at the Salzburgring in Austria. The new V4-powered YZR500 (0W61) was unveiled and Roberts finished 3rd with it in its debut race. He won his second race of the season at the fourth round in Spain before finishing 4th in Misano, 2nd in the Dutch TT, and 4th again in Belgium. However, he later suffered a DNF and an injury that took him out for the remainder of the season and ended up finishing 4th overall. Crosby did not score a win, but stood on the podium five times to finish the season as the title runner-up and top Yamaha, while Suzuki’s Franco Uncini won the title that year. Also of note was Spencer winning the Belgium GP, becoming the first Honda rider ever to win on a 500cc 2-stroke machine.

Though it was not the most stunning of results, the knowledge Yamaha gained over these two years of using different power units was extensive. Some of the technological breakthroughs seen were the rotary valve induction system with the 0W54, the bell crank rear suspension of the 0W60, and the 0W61's frame without lower cradle rails and a horizontally mounted rear shock. Without a doubt, these advances not only became the basis for later Grand Prix machine development but would also find their way into production racers and road-going sport bikes.

There was an urgent need to develop an engine with greater performance if Yamaha was going to best its rivals. The square-four that debuted the year before had more power than the previous in-line four, but the engine was also physically bigger and hindered handling stability—something that the riders were not happy with. So, Yamaha sought to give its riders what they wanted by developing a unit with a width and weight on par with a 250cc engine.

That was when an order came from the top to develop a V4 with a rotary disc valve induction system. It was a decisive order from then-director Noriyuki Hata. At the time, the development team was struggling with the layout for the fuel delivery system, because the orthodox method of using a side rotary disc valve intake did not take advantage of the V4 engine arrangement. The engineers were examining and discussing ways to make the engine even more compact, but development was simply not proceeding as they hoped.

But then, the mutterings of one engineer caused a breakthrough. “If the rotary disc could just spin between the cylinder banks, that could work...” Running with this, the project leader gradually gained confidence in the innovative concept. Instead of using a side-mounted rotary disc valve intake, with its disadvantages in terms of frontal projection area, positioning the carburetors between the cylinder banks would allow a single rotary disc to handle the intake duties for two cylinders. At first, the design did not match the performance of the conventional side rotary disc valve intake layout, but after repeated tests and prototypes, the YZR500 (0W61) was complete, becoming the first 500cc Grand Prix machine to use a V4. This was in February 1982, just before the season opener. The machine itself debuted at the second round of the year in Austria at the Salzburgring and took Roberts to the podium in 3rd.

The 0W61 YZR500 for 1982 also had its rear suspension mounted horizontally under the chassis, which did not fully capitalize on the slimness afforded by its V4 engine, and this led Yamaha to quickly begin developing a successor model. The idea was to pair the linked-type Monocross suspension from the square-four 0W60, which took Roberts and Sheene to a 1-2 finish at the opening round of the 1982 season, with a new frame with the same width as the V4 engine that would envelop it within like a cage. This marked the birth of the Deltabox frame, in which straight lines can be drawn from the top and bottom of the head pipe to the swingarm pivot, forming a delta triangle. This new frame design would first be featured on the new 0W70.

Yamaha gave that machine to Roberts and fellow American Eddie Lawson in 1983. Roberts was locked in a close championship battle with Honda’s Freddie Spencer on the V3 NS500, one which went down to the final round of the season. Spencer won by the narrowest of margins and so close was the duel that the season is still talked about today as one of the greatest dead heat showdowns in GP history. Over the course of the season, they took six race wins each, three 2nd place finishes each, and six pole positions each. The 0W70 frame used throughout that white-hot season-long duel has been advanced and refined over the 40 years since, and continues to be the de-facto standard for many sport motorcycles to this day.

At the “2&4” race held at Suzuka Circuit in the spring of 1984, Hiroyuki Kawasaki was riding the YZR500 (0W76). The day was a chilly affair, with sleet falling and a cold wind in the air. He had just returned to the Yamaha factory team the year before, and was riding a YZR500 he had helped develop himself. He took it to the brink of victory, but on the final lap, the machine lost drive—to his utter surprise—and he had to rely on what inertia he had left to propel him down the sloping final corner to the checkers at the finish line. The Honda and Suzuki machines behind him needed no invitation to come past, leaving him to finish 3rd. Kawasaki remembers it all clearly: “It was caused by an engine issue and I was so frustrated when it happened, but we came up with a solution right away to fix the problem and were able to have the modified engine flown to South Africa in time. That was the engine Eddie won his first race with.

At that year’s Daytona 200, Yamaha had the chance to take its 13th win in a row at the event. On the grid were three YZR700s (0W69), which were modified versions of the square-four YZR500 (0W60). Riding these machines were Roberts, who had retired from Grand Prix racing the year before, Lawson, who was the new star rider of the Yamaha factory GP team, and Taira, who was the reigning All Japan Road Race Champion. They were up against Freddie Spencer on the NSR500, but Roberts rode uncontested at the front, riding the full distance without a tire change to take the win. Lawson finished 4th and Taira came in 5th. The Japanese rider had decided to study Roberts’ and Lawson’s riding style and techniques, and later said, “Even when looking at my whole career, I learned a huge amount at that one race.

On March 24, 1984 at Kyalami Circuit in South Africa, Lawson rode one of the freshly delivered YZR500s from Japan to take his first win in the 500cc class. What got him to the top step of the podium was the fiery passion to achieve a goal and the strong bonds shared among motorcycle racers, each with their own status and roles to play. Some contributed to the machine’s development with input from actual races, some were older riders who shared riding techniques, and others were looking to win back a title.

The YZR500 continued its evolution for more than three decades, going through numerous iterations: eight versions of the in-line four, two versions of the square-four, and 18 versions of the V4. There were plenty of milestones during its lifetime, but the YZR500 (0W76) that Lawson won his first premier-class title on in 1984 was, from several points of view, one of those milestone machines. The Yamaha engineers, test riders, and the racers themselves all had their sights set on winning a Grand Prix title, and fueled by their passion for racing and Yamaha’s Spirit of Challenge, their strong teamwork constructed a motorcycle to do the job. Everything built into that machine would be passed on to Yamaha's engineers and racers, and eventually reflected in Yamaha’s future racebikes as well as production models.

On May 26, 1984, the early summer sun was shining down on the Sportsland SUGO circuit. The 250cc class of the All Japan Road Race Championship was essentially a TZ250 one-make series, with a few teams putting TZ engines into European-built frames. But that year, Honda entered its V-twin RS250R in the championship and on that day, Takao Abe rode it to a runaway Round 6 race win. This astonished not only Japan’s Grand Prix fans but Yamaha as well.

The company had refrained from factory participation in the 250cc Grand Prix championship after 1968, seeing the lower class to be a place for hopeful privateers to hone and prove their skills. Following the launch of the first TZ250 in 1973, Yamaha stuck to a policy of leaving 250cc class racing to production-based machines. In 1982, Frenchman Jean-Louis Tournadre rode a TZ250 in a closely contested points battle with Anton Mang on a Kawasaki KR250, successfully securing the title. The TZ250 remained at the top the next year, with Venezuelan Carlos Lavado taking his first 250cc title. However, with the subsequent appearance of highly competitive rival machines, it was time for the policy to change.

Yamaha’s work to develop a new 250cc machine did not start from scratch. The V4 engine from the 1985 YZR500 (0W81) was instead split in half vertically to form a V-twin and a model-specific clutch and transmission developed accordingly. The resulting YZR250 (0W82) made its Grand Prix debut at the final round of the 1985 season, the San Marino GP. Setting the fastest time in qualifying, the new bike’s potential was clear, but the title that year went to Freddie Spencer and the RS250RW.

However, the YZR250 was on the scene right from the first round of the 1986 season. Lavado was joined by West German rider Martin Wimmer and Japanese star Tadahiko Taira. The Venezuelan won the opening round and then won the third and fourth rounds in succession. Although he would occasionally crash out of the lead, his aggressive riding style won him many fans and he claimed his second 250cc title with six wins that season. At the final round in Misano, Taira came past 23 riders to take his first and only Grand Prix win in style. The YZR250 had also shown its outright speed by claiming pole position at every round that season (seven for Lavado and four for Wimmer).

The bike used a dual-crankshaft V-twin engine up until 1987 but adopted a single-crankshaft format from 1988. A dual-crankshaft V-twin has advantages in terms of vibration, but the simultaneous firing order led to issues when starting it up. To make engine starts easier, Yamaha chose to go with a 90° V-twin using a single crankshaft and a 270° firing interval. This single-crankshaft YZR250 is what would propel American John Kocinski to the 1990 250cc title, and the engine went on to be used in the 1991 TZ250 production racer as well as the TZR250 production sportbike. It was a textbook example of how the knowledge Yamaha gains through GP racing is passed down to its production motorcycles.

Between 1980 and 1990, the 500cc premier class was a largely American affair, with Kenny Roberts, Eddie Lawson, and Wayne Rainey essentially sweeping the field. But one cannot forget the many other popular racers that lined up beside them on the grid. The YZR500 lent itself well to a wide variety of riding styles at the top level.

Christian Sarron of France sharpened his skills on the TZ250 production racer and won the 1984 250cc title on a TZ adorned with a sky blue Sonauto livery. He then rode in the 500cc class for six years starting in 1985. At the time, Roberts’ hang-off riding style had become the norm, but Sarron’s was different. He kept his body to the inside when cornering, but held his head almost in line with the steering head in a more traditional “lean with the bike” style. His skill in steering the machine made his lean direction changes beautiful to watch and though his style was not flashy, it definitely pressured his rivals to perform. His sole 500cc race win was the West Germany GP in 1985, but he took 18 podiums across his six years in the premier class and is still held in high regard by French fans.

American rider Randy Mamola also began his Grand Prix career on a TZ250 in 1979. After riding in the 500cc class with Suzuki and Honda, he joined Team Lucky Strike Roberts for 1986 and ‘87. During his Honda days, he became known for his riding style in which his outside foot would come off the footpeg in the corners, but he did not continue it with the YZR500, where he showed impressive speed, especially in wet conditions. In his two seasons aboard the YZR500, he stood on the podium in 19 out of 26 races, and in 1987, he was a potent threat to his rivals much like Lawson was.

Kevin Magee made a name for himself riding 4-stroke machines. The Aussie may be more well known for winning the Suzuka 8 Hours back-to-back in 1987 and ‘88, but his name cannot be left out when discussing Grand Prix racing in the late ‘80s. After a first wildcard appearance in 1987, he rode full-time for Team Lucky Strike Roberts in 1988 and ‘89. He missed some rounds due to injury, but showed excellent consistency by finishing inside the top six in 21 of the 28 races he entered, including one win and one 3rd place finish. He was always right alongside his rivals in the push to the flag. When asked in the pit box how the bike was, he would always answer, “The brakes are spongy.” It was an answer that fit him well with how he would bravely dive into corners on his machine.

The YZR500s of the era were flexible and could be made to match each of these varying riding styles. Of these, the YZR500 (0W81) run in 1985 and ‘86 is said by the developers to have contributed to the bike’s strong handling stability. Previous V4 engines had both crankshafts rotating forward, but the 0W81 had the lower crankshaft rotating forward and the upper crankshaft rotating in reverse. The goal of the design was to reduce interference from inertia and give priority to rider feel. This dual contra-rotating crank design was kept until the final YZR500 model, the 0WL9, introduced in 2002.

The 1987 calendar had the most races for any season up to that point with 16 rounds, opening with the Japanese GP at Suzuka Circuit. It was the first GP event to be held in Japan in two decades and the first time for the 500cc class to come to the country. Riders for Yamaha, Honda, and Suzuki all climbed the podium steps that day to the cheers of fans, but for Yamaha, the day was meaningful in a variety of ways.

Honda’s 4-stroke NR500 returned to GP competition in 1980, but for the first two years it did not score a single championship point. So for the 1982 season, Honda rolled out a 2-stroke version in the NS500. In 1983, Kenny Roberts and his YZR500 were locked in an unprecedently close title fight with Freddie Spencer on the two-year-old NS500. Roberts narrowly lost out and Spencer was crowned champion, giving Honda its first Constructor’s title in 16 years.

That year’s fiery GP season made it clear who the major players for the title were, and the outcome of each race was always a topic of conversation among motorcycle racing fans in faraway Japan. Motorcycle magazines telling of the latest developments in Grand Prix racing from on the ground were flying off shelves. The fact that 1983 was also when the country recorded over 3.2 million motorcycle sales—a record that still stands today—was also of no small consequence. With all this happening, Japanese motorcycle journalists and other enthusiasts consider the battle between Roberts and Spencer to be the catalyst that led to the Grand Prix circus returning to Japan for the first time in 20 years.

Over the two decades that GPs were not held in Japan, Yamaha had been providing other ways for Japanese fans to experience a “real GP.” From 1977, once the GP season had concluded, the series’ top racers were all invited to compete at the TBC Big Road Race held at Sportsland SUGO in Miyagi Prefecture, Japan. With the Tohoku Broadcasting Company as the event’s title sponsor, Yamaha endeavored to help put on the event every year. It was a great opportunity for Japanese fans to get a real taste of the GP experience. The F750 class was initially the main draw, but from the autumn of 1981 onward the 500cc class took its place. It was possible to see 500cc GP machinery in All Japan races, but Japanese fans were enthralled by the prospect of seeing stars like Kenny Roberts, Barry Sheene, Graeme Crosby, Eddie Lawson, and others race them. Through this, the momentum to hold a GP event in Japan began to grow.

As these and other movements gathered steam, the long-awaited Japanese Grand Prix was finally held in 1987 at Suzuka Circuit. In it, Randy Mamola took a gamble on his final setup for his Lucky Strike YZR500 in the 500cc race. There was a blue wheel and tire in the pit box that day, which was a spare for Norihiko Fujiwara’s YZR500. He had finished 6th in the All Japan series the year before on a leased YZR500 and was making a wildcard appearance at the GP that year. Mamola used the blue wheel and tire combo during free practice and felt good with it, so he elected to leave it on his bike for the race. In the wet conditions, he took the lead on the first lap and had opened up a massive 42-second gap to Honda rider Wayne Gardner by the checkered flag, taking his 11th premier-class victory. The mismatched blue rear wheel may have looked temporary, but it was an admirable decision by the Yamaha team that showed their spirit of prioritizing the rider’s feeling instead of a stubborn adherence to a sponsor’s colors.

The decision rested on the shoulders of the team boss for the Japanese GP, Kenny Roberts himself. Though the closely fought 1983 season was more than three years behind him, it had been an unforgettable loss for both him and Yamaha. Though they had found retribution in different ways since then, winning in Japan after a 20-year wait in front of the home crowd did much to dispel the bitterness over that now-famous narrow loss.

The YZR500’s win at Suzuka that day was meaningful in many ways, from Yamaha’s strategy of putting the rider’s feeling first to making up for the disappointment of 1983. The win was like a badge of honor for Yamaha, as it had been waiting together with the other Japanese manufacturers and fans for a GP at home to become a reality while staging the TBC Big Road Race and other events for 10 years by that point.

Rainey became Yamaha’s star rider in the wake of Roberts and Lawson. He won his first premier-class title in 1990, but a major turning point in his career came prior to that at the Suzuka 8 Hours. After winning two AMA Superbike titles aboard a Kawasaki GPz750 and Honda VFR750, he earned a place on Kenny Roberts’ Team Lucky Strike Roberts for the 1988 season. He took 2nd in only his fourth race in the 500cc class at the Portuguese GP and ran with the momentum from that point on, taking another three podiums in a row in a strong show of talent. Rainey then participated in the Suzuka 8 Hours between GP events, teamed up with Kevin Magee. The pair took both pole position and the win in a performance many fans still talk about today.

Two weeks after the 8 Hours, the British GP was underway at Donington Park. Many expected to see a duel between Lawson and Gardner unfold, but what happened was quite different. Rainey rocketed off from 5th on the second row of the grid to take the holeshot. From that point he ran the rest of the race uncontested to take his first win. He had brought the fiery, passionate riding he used at the 8 Hours to the world stage. Rainey ranked 3rd overall by the end of the season, having made an excellent points haul and finishing nearly every race in his rookie 500cc season.

In 1989, Rainey’s second year of full-time GP competition, he finished as the title runner-up with 13 podiums in 15 races, including three wins. His YZR500 for the season was the 0WA8, which featured a data logger that became essential for managing the electronics and tuning the bike’s setup. It measured and tracked ride data across 30 channels, including engine rpm, throttle opening, YPVS operation, brake pressure, and tire slippage. This allowed engineers and riders to share information and thereby set a direction to go in for machine setup as well as better overcome issues.

It was the data and knowledge gained in 1989 that led to the creation of the 1990 YZR500 (0WC1). It boasted higher power and entirely new dimensions, with the head pipe located closer to the rider and a different rake angle. Rainey rode it to 14 podium finishes in the 15-round season—standing on the top step seven times—to win his first GP title, helping Yamaha win its sixth Constructor’s title in the process.

The shift toward digitalizing information and sharing it gave the 0WC1 a boost in competitiveness, and the machine became a pivotal part of Yamaha’s 1990s GP challenge and even its corporate philosophy at the time.