I have a little stick time in a rotary powered aircraft. A Coot amphibian with a pilon mounted Mazda 12A with electronic ignition, 2:1 reduction with a 5 blade ground adjustable prop. It slows down to 500rpm and takes off at about 6800rpm. Very smooth operation but very high fuel consumption. Also extremely loud. It had nitrous oxide injection which added another thousand rpm for takeoff. It got you up on the step and off the water. About 2100 lbs. empty weight. Not for the light sport pilot.
Joe Eagle Creek, Ore.