The Versys has a 650 cc four stroke liquid cooled parallel twin engine that was changed a bit to get more torque. This engine is inspired by the Ninja 650R.
The inlet and exhaust cams were outfitted with shorter valve duration in order to increase the torque. This results in better throttle at lower revs because the peak torque has been moved further down the rev range. To make the power even smoother a balance tube was added right between the exhaust headers.
The Versys was created for pavement riding on back-roads and city roads. As a result, the fuel injection system was revamped. It was fully mapped so the mid-range from 3000-6000 revs would receive a nice and strong response from the throttle.