This is a recently restored 1977 Hartman Blue Streak Go-Kart that is powered by not one but two Yamaha KT100 two-stroke engines. Double-engined karts like this became popular in the 1960s and 1970s, as they offered a lot more power and speed than their single-engined counterparts.
Go karts like this have long provided an affordable entry point into motorsport for young and old alike. In some respects, karting is the very foundation of modern motorsport as almost all professional drivers came up through the rough and tumble karting ranks, proving their mettle.
Here we see John and Kathey Hartman with one of their creations, topped with one of Kathey’s many racing trophies. Image courtesy of Karter News.
Hartman Go Karts: A History Speedrun
Hartman Engineering was founded in 1947, just two years after the end of WWII, by John Hartman who was an accomplished machinist. The company was established in a 4,200 square foot shop in Montrose, California, and they began experimenting with go kart design and production by the late 1950s.
Given John’s engineering background, his karts were widely recognized as being among the best in the nation. They had stiff tubular steel frames, front disc brakes, rack and pinion steering, and excellent ergonomics.
Kathey Machala became the go karting Ohio state champion in 1964, racing against a field consisting almost entirely of men. She would win countless races, culminating with winning the 1966 Open Light National Championship.
It would be around this time that she would meet John Hartman, the two quickly became inseparable and married soon after. Kathey would become a factory driver for Hartman Engineering, helping further raise the company’s profile and add to its list of wins at the state and national level.
Today the original Hartman go karts from the 1960s and 1970s are highly prized by collectors and by vintage kart racing aficionados, with the twin engined examples typically attracting the most interest.
The Twin-Engined Blue Streak Go-Kart Shown Here
The kart you see here is an original 1977 Hartman Blue Streak Sprint Go-Kart with the twin engine arrangement in the rear. Adding a second identical engine offered early kart racers an easy way to double their power without having to resort to buying a larger, more costly engine.
This kart is powered by a pair of Yamaha KT100 100cc single-cylinder, two-stroke engines that are said to have been rebuilt by engine builder Matt Jones of Yamaha of America. Power is sent to the rear axle through Tomar centrifugal clutches.
Kathey Hartman is undeniably one of the all-time greats, and she deserves to be far better-known than she currently is. Image courtesy of Hartman Engineering.
The kart has an Azusa steering yoke with black grips, a clear molded OTK fiberglass seat, and an aluminum floor pan. It rides on 6″ Douglas cast magnesium wheels fitted with Hoosier racing slick tires. It has an MCP slotted disc brake mounted on the rear axle, a Hartman fuel tank, and the frame was repainted during its refurbishment.
This kart is now being offered for sale out of Placentia, California with a bill of sale. If you’d like to read more about it or place a bid you can visit the listing here.
Images courtesy of Bring a Trailer
Articles that Ben has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
