Several years back Rotax dropped what was IMO the best engine they did for microlights. The liquid cooled 462.
Lighter than the 582. Single carb made it very economical and being liquid cooled it was quieter and more punchy than the 503. Just about the right power output for a 390 / 450kg aircraft.
Pity they didn't develop it to bear twin DCDI ignition as in the other models.