The troubled Kawasaki KR500 engine and design flaws temporarily stalled Eddie Lawson’s career in MotoGP.
Much is being made about Suzuki’s sudden withdrawal from MotoGP. But back in 1982 Kawasaki took the same option, which involved future multiple world champion Eddie Lawson.
To compete at the highest level of motorcycle road racing, you need to take on the ultimate challenge — the Senior class of Grand Prix racing, once called the 500cc World Championship, now called MotoGP.
This cauldron of competition mixes the rare talent of riders with the calculated and methodical approach of the technicians involved. To survive just one season the riders and technicians need to believe in their project. To win, they need the unwavering support of the factory providing the machinery. This may take several seasons as a prototype is developed into a race winner that then has a chance of becoming a championship winner.
In 1980 Kawasaki was the minnow in the shark’s pool that was 500cc motorcycle racing. It would continue in this class for just three seasons as factory support faded. Despite having large resources, Kawasaki committed a relatively small team to a contest that required a massive commitment. Despite showing promise, its KR500 was always too heavy and too slow to be a title winner despite featuring some radical technology.
This venture also temporarily stalled the 500cc career of Eddie Lawson, who nevertheless survived the experience to go on and win four 500cc world titles with three manufacturers in the space of just six years.
How it all began
Kawasaki’s plan to contest the 500cc class was formulated in 1979 and put into action in 1980. There are many theories as to why Kawasaki made this decision, but the one that makes most sense is the inspiration that Yamaha’s win in 1978 provided, plus the fact Kawasaki had won the 250cc/350cc double that year. South African Kork Ballington had become one of only three riders to achieve this (Mike Hailwood, 1967/Walter Villa, 1976).
His efforts, along with several other riders on Kawasakis, gave the company the Constructor’s title 250cc/350cc double in both 1978 and 1979. It would repeat this double in 1981 ridden by West German Anton Mang, the midway point of Kawasaki’s involvement in the 500cc class.
In 1978 Yamaha’s new rider, American Kenny Roberts, had become the first American 500cc world champion. As well as dethroning Brit Barry Sheene from the top seat he had occupied for the previous two years, Yamaha had defeated Suzuki for the first time since Giacomo Agostini’s 1975 title that gave both him and the factory world titles (rider/constructor).
Third in the title chase that year was another Yamaha rider, Venezuelan Johnny Cecotto. However Suzuki riders filled all the places on the points table down to position 30, with only four Yamahas featured outside the top three. But Yamaha’s effort gave it second in the Constructor’s title, with 139 points to Suzuki’s 146.
This showed that the right motorcycle, with the right rider, could beat much more fancied and more available motorcycles. And so Kawasaki joined the fray in 1980. The Kawasaki KR500s we feature here are from its two most successful years, 1981 and 1982.
1981 Kawasaki KR500 Engine
The 500cc 2-stroke engine (54mm bore x 54mm stroke) was based on the championship-winning KR250cc rotary-valve, tandem twin configured into a square-4-cylinder layout. This was a similar layout to Suzuki’s original RG500 (eventually Suzuki went to a “stepped” cylinder layout), which had been around since 1974 and was the privateers’ race bike of choice in the late 1970s.
The KR500 engine had a dry clutch and 6-speed gearbox, with a variety of gear ratios to suit the various GP circuits. Where the KR500 differed from its rivals was the use of a full aluminum monocoque frame, designed with some input from Kawasaki’s aircraft division. It is interesting to note that Honda’s first version of the ill-fated oval-piston, 4-stroke NR500 in 1979 also featured a monocoque chassis.
Honda soon reverted to a conventional tubular frame after structural failures, engine overheating and accessibility problems. However, the monocoque on the KR500 featured robust reinforcement in critical areas, including struts running from the headstock to the front of the engine. Two additional plates, to which the footpegs were mounted, gave extra support to the swingarm area. The 8.45 gallon (32 liter) fuel tank was contained within the monocoque.
After limited testing in the U.K., Kork Ballington debuted the KR500 at the 1980 Grand Prix season opener at Misano, Italy, retiring partway through the race. He finished 13th at Jarama, Spain, then eighth at Paul Ricard, France. An up-and-down season that saw him finish 12th in the points featured best results of fifth at Imatra, Finland, and seventh at Silverstone, U.K.
Several improvements were made for 1981. These included reducing overall dry weight by 11 pounds to around 293 pounds, and stiffening the chassis even further after steering damper failures. The front engine struts were removed as they had caused extreme chassis vibration. The engine was retuned to deliver more mid-range power to boost acceleration out of corners.
One of the biggest changes was the introduction of a mechanical anti-dive system on the front fork. Several manufacturers were experimenting with ways to limit suspension compression under brakes and both mechanical and hydraulic systems found their way onto street bikes in the mid-1980s. However, ultimately it proved to be a blind alley. The theory was that keeping the steering head angle constant would aid handling, but many riders didn’t find the system intuitive.
Perhaps it masked the KR500’s real problem. The monocoque chassis reduced frontal area for a potential high-speed aerodynamic result, but it was too long, too low, and the rear shock absorber tended to overheat as the long Grand Prix races wore on. There were also problems with the rear tire overheating and losing grip. None of these problems were properly addressed over the KR500’s short lifespan.
The Kawasaki was around almost 4 inches longer than its rivals. While this gave it great stability on long straights and sweeping corners, it was a real handful to get turned quickly into chicanes and tight corners. Despite weight loss it still weighed some 33 pounds more than rival Suzukis and Yamahas. Nevertheless the KR500 quickly started to show real potential.
Australian star Gregg Hansford, Ballington’s rival in the 250/350 GP classes on a Kawasaki, put the new version of the KR500 on pole at Italy’s Imola 200 at Easter, the first major European race of the season. However a race crash sidelined him for two months. After his return to GP racing, another major crash at Spa-Francorchamps in Belgium ended his career.
Meanwhile, Ballington built up momentum over the first few GPs, with three top 10 finishes in the first five races. Then came the dream finish: third at Assen and the fastest lap of the race. He finished third again at Imatra and fourth at the season finale a week later at Anderstorp, Sweden, for eighth place overall in the title chase.
As well Ballington came second in the U.K.’s Shell 500 championship to Kiwi Graeme Crosby’s factory Suzuki (Croz came 5th overall in the 1981 world 500cc title chase and second in 1982 on a Yamaha). The Shell 500 series was described at the time as being a “home equivalent” of the world title with many international riders competing.
The KR500 pictured here was the actual machine that Hansford crashed on at Spa. The bike was tested and developed in Australia before being taken to Europe.
1982 KR500
Kawasaki may have had a tiny KR500 development team, led by the determined and forthright engineer Kinuo “Cowboy” Hiramatsu, but it poured a huge effort into the final version for 1982. The detail revealed in these images of the KR500 that Eddie Lawson raced in the U.S. in early 1982 is simply stunning. Lawson may not have raced it in Grands Prix, but it was his introduction to the experience.
For example, the steering yokes, crafted from aircraft aluminum, are fitted to a beautifully-designed magnesium steering head plate that bolts to a new version of the monocoque frame. Tapered spacer plates could be fitted to rapidly alter steering rake without disturbing the fork yokes.
The front and rear axles have a unique mounting arrangement that allows quick adjustment for steering trail via eccentric washers.
The intricate front brakes are manufactured entirely by Kawasaki. The precise detail continues with gold anodized “stinger” mufflers that have screw-cap ends to allow quick repacking. The bodywork is carbon fiber in a time when the use of this was in its infancy.
But look closer and you see the same rangy wheelbase and low-slung chassis that was the Achilles Heel of the earlier version. However, the swingarm was slightly shorter than before.
For 1982 the development team tried to reduce weight and add some flexibility to what they now considered was an uncompromisingly rigid design. The result was a completely new semi-monocoque spine that required a separate aluminum fuel tank for the long European races. Ballington spent a day at Kawasaki’s headquarters getting this tank molded to suit his dimensions and riding position using a polystyrene block as a dummy. This larger tank augmented the smaller amount of fuel contained in the chassis.
Strangely, Kawasaki’s engineers then added weight by changing from magnesium engine cases to aluminum (but retaining the magnesium engine covers). Continuing with a mechanical anti-dive suspension system rather than a lighter hydraulic version didn’t help with weight reduction either.
However, a revised ignition system and other more subtle engine changes made the KR500 perhaps the most powerful engine on the 500cc grid that year.
Eddie makes it big
A KR500 was sent to the U.S. for the first big domestic race of 1982, the Daytona 200. Eddie Lawson was chosen to race it. He was a rising star under the tutelage of long-time Kawasaki U.S.A. race manager and development engineer Randy Hall. The relationship was similar to that of Gregg Hansford and his long-time Australian crew chief and mentor Neville Doyle. Both riders had spent previous years racing in their respective national 250cc classes.
In Lawson’s case, he won four national championships in three years, but his two 250cc titles on KR250s are rarely mentioned. Rather it is his results on Kawasaki’s 4-stroke Superbikes, which culminated in the roadgoing 1982 Kawasaki KZ1000R Eddie Lawson Replica, that get the attention.
But Lawson had big ambitions to go Grand Prix racing. His first step would be the Daytona 200, with the KR500 entered in the AMA Formula 1 class for season 1982.
Kenny Roberts qualified on pole on his Yamaha Grand Prix 500, setting a new lap record. Second was Graeme Crosby on a Yamaha TZ750. Lawson qualified fifth, an impressive debut among some of the world’s top riders on exotic factory machinery.
Roberts led for the first eight laps until his Yamaha seized and he retired. Lawson surprised everyone by taking the lead and holding it until his scheduled fuel stop on lap 20. As well as proof of Lawson’s riding ability, it also underlined how powerful the upgraded KR500’s engine was. Sadly, eight laps later Lawson was out with transmission issues.
Lawson next raced the KR500 at Road America, Wisconsin, in May. He finished second to Wes Cooley’s Suzuki Katana 4-cylinder, 1,000cc 4-stroke after battling a mysterious loss of engine power.
His next outing was at the high-profile Champion Spark Plug 200 meeting at California’s Laguna Seca Raceway. Kenny Roberts, Freddie Spencer and Randy Mamola were among several GP riders taking a break from Europe to compete.
Despite meticulous preparation, the KR500 developed a problem before the first leg of the Formula 1 races and Lawson joined it three laps down. He crashed out of the second leg, cracking a vertebra in his neck. This forced Lawson out of the rest of the Formula 1 season, but he bounced back later in the year to win his second AMA Superbike championship.
Lawson planned to go to Europe in 1983 and race for Kawasaki, but the factory withdrew from Grand Prix racing, siting the effects of a declining world economy. Lawson was soon snapped up by Kenny Roberts’ Yamaha team, overseen by team manager Kel Carruthers.
More trouble
Over in Europe, Ballington battled various issues with the KR500, many of them due to its weight and wheelbase. There were no podiums or finishes higher than sixth, but over the 12 races he met the checkered flag within the top 10 nine times. The end result was ninth in the championship with Kawasaki fourth in the constructors’ title behind Honda, which had returned with an all-new V3 2-stroke.
Moving on
A new era was about to start in Grand Prix 500cc racing, but Kawasaki wouldn’t be a part of it. Perhaps the difference between Grand Prix racing and the Formula 1 and various domestic championships the KR500 was also eligible for is shown in Ballington’s easy win in the U.K.’s Shell 500 series. He then signed off the KR500’s three-year lifespan with a fastest lap and second overall at the post-season World Cup at U.K.’s Donington Park. That must have given him immense satisfaction as he was racing against a cross-section of the Grand Prix grid that had regularly beaten him earlier that season.
Ballington’s talent certainly wasn’t lacking, and neither was the ability Lawson displayed briefly in the U.S. What was missing was factory commitment at the highest level to help its racers and technicians achieve the goal of a world Grand Prix 500cc championship.
The first hurdles had been overcome but Kawasaki management didn’t have the incentive to continue the grueling contest. MC
