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Kawasaki KR1 – Fastest Ever Mass Produced 2 Stroke

In 1988 the Kawasaki KR1 was released. It was a road-going race replica two-stroke with a difference, it was one of the only bikes in the category that wasn’t based on an actual racing motorcycle. 

It was a standalone production road-racer built to capitalise off the popularity of 250cc machines at the time like Suzuki’s RGV250 and Yamaha’s TZR 250. 

The roots of the KR1 could be traced back to Kawasaki’s early days of GP two-stroke success; however, it was a new beast altogether and very much unlike the prior KR250

The KR-1 and later KR-1S would have a 4 year run until 1992. While a relatively short lifespan, it is one of the most sought after bikes of the era today, simply because it became an icon pretty quickly.

Without further ado let’s take a look at the legendary Kawasaki KR1.

Kawasaki KR1 Review

Kawasaki KR1

Engine and Transmission

The KR-1 liquid cooled engine was loosely based on Yamaha’s TZR engine design, a two-cylinder, reed valve induction with a 180 degree firing angle. 

Kawasaki also implemented the K.I.P.S (Kawasaki Integrated Powervalve System) which was shared among their other two-strokes in the line-up. The end goal of K.I.P.S was to broaden the power delivery across the entire rev range.

The engine for the KR-1 remained pretty much the same throughout all the produced models. The reason being they simply got it right the first time.

It was the fastest of the class beating the RGV250, NSR250, TZR 250 and the Aprilia RS250.

Kawasaki were also the first of the Japanese ‘Big Four’ to pull their 250cc two-stroke from their line-up in 1992 despite it being a roaring success. They also didn’t go on to turn their simple parallel twin engine into a V-twin for enhanced performance.

Perhaps they wanted to get ahead of the game with emission laws and focus their attention solely on their four-stroke machines. Whatever the reason, it increased the public’s fascination with the KR-1 series and the bikes are highly coveted to date. 

The engine on early models suffered from reliability issues. Later KR-1S motorcycles had nickel plated cylinders which were expensive to re-bore and replace. On the other hand they were easy to work on, easy to tune and therefore perfect to get the most potential out of and race. 

The power to weight ratio was impressive as the KR-1 only weighed in at 123kg, the engines 50 plus horsepower was more than capable of propelling the bike forward, very quickly at that. 

It is the very nature of the bike that it wants to go quicker, sitting at 70mph is not where it is comfortable and it tempts you to twist the throttle to keep on going. 

For a bike not based on a race machine it had impressive performance and was actually the perfect race machine. Owners were quick to tap into this and knew they had a winner, with a free-flowing engine right up to 12,000rpm.

A 6 speed cassette gearbox further increased owners’ temptation to play with the gearing and get it ready to win races whether that be on the track or a race to the cafe with your mates.

Chassis, Suspension, Handling, Brakes

It wasn’t just the engine that made the Kawasaki KR1 quite so superb but it was the chassis that contained it. 

A lightweight frame, that’s rigidity only increased throughout the models, was huge and wouldn’t have looked out of place on a 500 cc, let alone a 250 cc motorcycle. 

For the time it was also technically advanced with features that usually were only seen on the race bikes. Adjustable suspension front and back, low profile tires and brakes that were semi-floating discs. 

It was a serious bike built to be exceptional and change the standards owners had come to expect of the 250 cc class.

The riding position as a result of the big frame was less cramped than the competitors and was quite comfortable even on longer journeys. 

However, the mpg was poor as with most two-strokes so, even if comfort was an issue it wouldn’t be long before you were needed to stop for fuel anyway and the opportunity could be taken to stretch your legs. 

The steering of the KR-1 was known to be sharp and quick, the KR-1S was even sharper as a result, a true weapon for both the street and track. 

Although, it wasn’t all good news, the lightweight chassis combined with a higher power output would lead to some dubious moments at speed, tank-slappers could be an issue. 

A well fitted steering damper would put pay to the issue and get the KR-1 performing as it should. 

The bike wasn’t the best looking in the class but it attracted adrenaline junkies and a cult following was quickly created and the fascination still remains today. 

Kawasaki KR1 Variants

The first of the KR-1 models had the designation B1 and B2. Largely down to the booming market of the 250 cc class as a whole by 1989 the KR-1S was released and these had the designation of the C and D series. 

Total production of the Kawasaki KR-1 across all series was said to be less than 10,000 worldwide which makes it highly rare and collectable today.

Kawasaki KR1S
The KR-1S is the most coveted with improvements made to the chassis, brakes and suspension that made it superior to the earlier model.

By 1989, the cult of the Kawasaki KR 1 had a massive following, driven by proddy racing successes. At the final round of the British Supersport 400 Championship in Brands Hatch, KR-1’s filled seven of the top ten positions with KR-1 riders Ian McConnachie winning the championship and John Reynolds finishing a close second.


The KR-1R was produced to compete directly with the SP models of the other Japanese 250’s, it was most suited to the racetrack and to compete in production model races. Only around 180 of these are said to exist.

For the New Zealand race circuit 12 Sports Production models were built; they featured the bigger ‘R’ model carbs and different porting and compression ratio.

The Kawasaki KR-1 wasn’t a huge commercial success and the evolving Suzuki RGV250 made it impossible for the KR-1 to compete in the market. By 1992 Kawasaki pulled it from their line-up and shifted their attention to their four-stroke racers.  

Kawasaki KR1 Specifications

Engine and Transmission Spec’s

  • Engine – Two-stroke, parallel twin
  • Capacity – 249cc
  • Bore x Stroke – 56 x 50.6mm
  • Liquid-Cooled
  • Compression Ratio – 7.4:1
  • Induction – 2 x 28m Keihin PWK carbs
  • Kick-Start
  • Max Power – 55 horsepower at 10,500rpm
  • Max Torque – 36Nm at 10,500rpm
  • Transmission – 6 Speed
  • Final Drive – Chain

Chassis and Dimension Spec’s

  • Front Suspension – Air-assisted telescopic fork
  • Rear Suspension – Bottom link Uni-Trak with air adjustable gas shock
  • Front Brakes – 2 x discs, 4 piston caliper
  • Rear Brakes – Single disc, 2 piston caliper
  • Wheelbase – 1,365mm
  • Seat Height – 855mm
  • Dry Weight – 123kg
  • Fuel Capacity – 16 litres

Kawasaki KR1 Top speed

MCN states that the KR-1S was the quickest mass-produced two-stroke bike ever with a top speed of 139mph being recorded. 

The standard KR-1 is said to have been capable of 131mph.

Kawasaki KR1 For Sale

The KR-1 never actually made it to the US at the time although some models have since found their way through the cracks and have been imported by privateers. 

There is quite a large price range for a KR-1 in the US starting from around $7,000 to upwards of $15,000. 

This 1989 model has an asking price of $8,000, it has been upgraded where possible as it has been competing in the USCRA. 

Whereas this older advert on Raresportsbikes from 2018 is showing a KR-1S listed for $15,000.  

In the UK prices vary from £3,500-£8,000.

eBay UK
Kawasaki KR1 250 For Sale Kawasaki KR1 250 For Sale
From £5250

Several KR1's currently listed on eBay including a few classified ads ranging from £5250 to £8000

I may earn a commission if you make a purchase, at no additional cost to you.

There are some serious things to consider before purchasing a Kawasaki KR1, largely down to the fact that so many of them were raced. Combine that with dubious reliability to begin with and the used market stacks up the odds against those looking for a quality example. 

  • K.I.P.S valve linkages are now to break, so be sure to check all is working as it should
  • Bodywork was known to be fragile so look for breakages and ensure that parts all match up with correct numbers etc
  • KR-1 pistons were quite weak and so many owners replaced them with Yamaha TZ pistons
  • RGV 17” wheels are often fitted to replace the original 18” wheel to improve handling

While some of these modifications improve performance they are not in keeping with a wholly original model, so it will depend how important that factor is to you as a buyer.

To ensure you are not buying a dud, avoid bikes that are priced at what you think is too good to be true. They will likely have raced a lot, been through the wars and therefore you will be purchasing nothing but problems. 


There are few KR-1’s still in existence simply because so few were produced when compared to other bikes in the same class. 

A short lived legend but a legend nonetheless, a bike worthy of applause and admiration. 

One that in my opinion deserves to be revived. One that should be kept in museums, but also one that should enter into classic races the world over, give the production road bike a chance to be a production racer to win and set new records.

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