The world's lightest four-stroke 250 single engine

Four stroke dirt bikes were once overweight and underpowered, but that’s changing fast. Specialist off-road motorcycle manufacturer Husqvarna has disclosed details of a new 250 four-stroke engine it is testing that weighs just 22 kilograms. Though the motor may be small, there has been no significant saving in weight as the new bike, which is likely to be available in limited quantities by the end of the year, comes in at 92 kilos dry – the same as the Yamaha YZ250R and Suzuki RMZ250.

The motor uses titanium valves in a radial layout and Husqvarna, is claiming its dimensions are some 13 percent less than its competition, though we’re not quite sure what that means.

The attached images show former World 500 MX champ Andrea Bartolini developing the new bike in his role at Husqvarna R&D.