The Leonardo is not air but water cooled. The first model became available in 1996. In 1997/1998 the 151ccm hit the market and since then its has been faceliftet two times. The first facelift integrated the rear blinkers into the bodywork and teh radiator grill got a different look. The second facelift gave it a bigger screen as standard as well as some changes to the bodywork for better wind protection - and an integrated luggage rack.
The original 125ccm (and 151ccm) rotax engine has only changed in detail. The 250ccm is basically the same engine as the one in Yamaha´s Majesty