Mini kart

While browsing ads on an online “flea market”, I came across wheels from a children’s quad bike. They also came with hubs and steering knuckles. The price was very attractive, and I bought them with a “long-term plan”. They gathered dust in the garage for a couple of years until I decided to build a mini-kart for my son.

I got out the wheels, pipe scraps left over from building a buggy from an “Oka”, found an axle from an old kart and a steering wheel from some “Lada”. A neighbor from the garage shared shock absorbers from a “Minsk” motorcycle (for the front axle) and from an “Izh” (for the rear).

I used a Chinese engine – Lifan 6 hp, from a tiller, with a centrifugal clutch. (Looking ahead, I note that it turned out to be a bit weak.) I spent a long time selecting a driven sprocket for the axle so that the tooth pitch matched the drive sprocket already installed on the engine. One from the timing belt drive of a “Chevy Niva” engine fit. I adjusted the chain length by removing extra links. I then hammered the connecting pin into place and slightly flared it. I installed a chain tensioner in the form of a roller on a lever: on one side – a roller, in the center – an axle, on the other side – a spring. The gear ratio turned out to be around 3. For such a design and this engine it’s a bit low, but I couldn’t find a more suitable sprocket.

In the brake system, I used a clutch master cylinder from a “Volga” as the main brake cylinder, and a working brake cylinder from a Chinese motorcycle.

The front suspension is a double wishbone, without any adjustments. And this was a big mistake on my part. Moreover, I forgot to set the caster (longitudinal angle of the steering axis), which negatively affected handling.

The rear suspension is a swingarm, on which both the axle and the engine are mounted. The chain tensioner is a roller on a spring-loaded lever.

The steering rack is completely homemade: made from two pipes, a chain from a moped and a sprocket from a bicycle. The bushings are made from polypropylene pipe.

Since I worked without rushing, building the machine took a year. The result was quite functional (considering the aforementioned shortcomings), fine for children’s use. But – I’ll repeat again – before picking up tools, you need to think through the design better.

Now the mini-kart is already disassembled, I used it for parts for a new project – a quad bike. It’s currently under construction. Well, I gave the frame to a neighbor’s boy who also wanted to build a machine with his own hands. Maybe he’ll do better?

«Modelist-Konstruktor» № 4’2025, Vladimir KOTMYSHEV, amateur constructor