I have a Saito .82 with APC 14 x 4W prop on my Twist. It will fly fairly flat spins and even climb slowly on most occassions; I have to catch something just right, ailerons I suspect. Here is how I enter a climbing inverted spin: set elevator and rudder for maximum throw on high rate, fly inverted into the wind, slow the plane down to stall speed, give the plane full power and full down elevator suddenly and at the same time, just as the plane pitches back to inverted flight give it full right rudder, then start maneuvering the ailerons a little left or right to get the type of spin you want. Also use less than full elevator, rudder, and\or power after entering the spin and the spin will look much different. Max throw is necessary to help ensure the wing stalls; no stall, no true spin. Recovery is easy, just return all controls to neutral and select low rate on elevator. If you don't select low rate elevator, at least use it judiously to prevent a secondary stall. My Topcap started to do flat spins exceptionally well once I changed the engine to get more power. On the other hand my Fazer which is exceptionally over-powered (Jett .76) won't spin well at all. My point being I am sure that a number of variables affect how well a plane will spin - or not spin.