Meet the ultimate lightweight, big bore 2-stroke street weapon…
The Kawasaki KX500 is one of the most notorious motorcycles ever built — a fire-breathing 2-stroke legend of motocross and desert racing whose power delivery has been described as fearsome, violent, and explosive. It was the most powerful dirt bike of all time, outpacing the Maico 501 and the mighty Honda CR500. Even today, more than thirty-five years later, modern 450cc 4-strokes make about the same peak horsepower as the KX500 of the 1980s. The mighty KX has fared well against a new KTM 450XC in head-to-head tests, while Dirt Bike magazine has gone so far as to call the KX500 “The One Bike to Ride Before You Die.”
Enter Mark Miller (@nojoke2stroke) of Texas, whose Yamaha RD400 street tracker we featured last year after falling in love with it at the Handbuilt Show. Mark wanted the challenge of getting another bike into the show. This time, the heart of the build would be a fire-breathing KX500 engine. Making the shoulder-dislocating power of that liquid-cooled, 2-stroke 499cc motor work in a functional street bike would be no small challenge, but Mark was up for it.
Similar to his last build, Mark used parts from several different bikes to create the one he wished the factory had built. The included a KX500 engine, a KX250F chassis, and a ZX6-R front end. The result is the ultimate 2-stroke cafe racer, “Street Lethal” — a 230-lb, 70-hp street weapon with tuned suspension and hand-built carbon bodywork.
Below, we get the full story on this aptly named build, along with a killer set of photos from Jason Lehecka.
Kawasaki KX500 Cafe Racer: Builder Interview
• What’s the make, model, and year of the bike?
Motor: 1991 Kawasaki KX500
Chassis: 2009 Kawasaki KX250F
Front End: 2009 Kawasaki ZX6-R
• Why was this bike built?
Who wouldn’t want a KX500 street bike with a Tom Morgan Racing ported and balanced motor? And I wanted to utilize a few Craigslist items that have been collected over the years.
• What was the design concept and what influenced the build?
Challenge to build the ultimate Café Racer. Extremely light with “pick any gear and wheelie” horsepower. Huge influence came from Roland Sands’ CR500 café build and the awesome guys at Revival Cycles for the inspiration to get another build into the Handbuilt Show.
The Honda and Kawasaki big bore dirt bike 2-stroke powerplants are arguably the best motors ever built for their purpose. Making this motor work as a functional street bike was a huge challenge that I didn’t want to shy away from.
• What custom work was done to the bike?
I wanted the weight and flickability of a dirt bike, the power of a big bore 2-stroke, and the handling of a modern street bike. The final weight is under 230 lbs (104 kgs) and horsepower is in the range of 65 to 70 HP. The approach was minimalistic, but no shortcuts on handling and dependability.
The aesthetics of the build come from the custom carbon fiber tank and tail/seat hand built in my garage. 200+ hours after building plugs, molds, and parts the final product turned out better than expected.
Mating the dirt bike KX250F chassis with the KX500 engine and ZX6-R front end was a huge challenge. I got some big help from Matt from Working Man’s Custom to help me get the motor mounted correctly and several other aluminum mounts including the CR500 pipe and silencer. Matt is also a genius leather craftsman and once again built a fantastic leather seat.
Getting the chassis and suspension to work properly was another big undertaking. Doc from 812 Suspension lowered, revalved, and resprung the shock along with new springs in the forks to make a perfectly balanced, yet still aggressive, ride.
The paint came out beautifully again from Josh at Trevino Customs. Once again he was able to color match his creativity to the style of the bike.
• How would you classify this bike?
Curb-hopping, neighbor-frustrating, mosquito-killing, café racer!
• Was there anything done during this build that you are particularly proud of?
I am really thankful for Google for providing invaluable information through search and video. This bike is really proof that anyone with hands, feet, brain, and access to the internet can accomplish almost anything they want. With countless hours of research I was able to build a proper electrical system with a lighting coil, a full wire harness to run a headlight/tail light/turn indicators/speedometer, determining how to run spoke wheels front and back, secondary gearing, and my biggest challenge of building a lightweight and strong fuel tank and body kit from Carbon Fiber.