Super Sportsters have been known to get "stuck" in inverted flat spins with an aft CG. Be on the reverse rudder just after centering the sticks for recovery.
Upright spin: Fly straight up to a huge altitude. Stop the plane on an upline by reducing throttle. When if falls backwards, put both sticks in the bottom same (right or left) corners. After a revolution or 2 slowly reverse the aileron and add a click or 2 of power at the same time.

Inverted spin. All the same but use down elevator.

Again, be on the reverse rudder and power just after centering the sticks incase it gets "stuck". I've flown for only 5 years and have already seen (with my own eyes) two Super Sportsters go in on their backs, because the pilot did not know how to stop the spin.

After you've done it several times, start to experiment with moving the sticks around. What happens if you start the spin, then, without changing the ailerons, add 3 or 4 clicks of power. After that throw the rudder opposite and hold the power. Start real high with that one!