A minibike, also recently known as a mini moto or pocketbike, is a miniature motorcycle. Most traditional minibikes use 4-stroke engine to turn the rear wheel via a chain. They are similar to a lawnmower engine but require a horizontal shaft while a lawnmower uses a vertical shaft. This is why a lawnmower engine cannot be used to make a minibike, contrary to popular belief. Some models use 2-stroke engines, and electric-powered models are also available. The 2-stroke motor produces a loud, whining buzz and a more polluting cloud of smoke as exhaust if not properly tuned. These features, along with the minibike's small size, mean that minibikes are rarely street-legal.