Dick has pointed you in the right direction, in order for any airplane to spin, it must first stall. To stall any airplane the wing must exceed its stalling angle. To do that the control surface that controls the wing angle to the relative airflow must have enough `power' (lift) to pivot the wing about the cg's lateral axis to achieve that angle at whatever speed the airplane is flying at. If you have a `standard' setup then you will be using a tailplane/elevator setup. With the cg in a `normal' position(25~33%) this amount of elevator movement will be found by experiment, ie, you have to fly the thing. If you think that the model is too elevator sensitive with all that movement then might I point out that we use proportional radios now, and you must learn to be more gentle with the elevator stick. It is not a switch, we stopped flying them sorts of radios, oh, years ago. If you feel that some sort of assistance is needed then a bit (30%) of expo will help. Properly done you can now land the thing properly too, as you will be able to control the models' airspeed all the way to the stall, which is a real help when trying to land at the minimum speed to prevent bouncing.
Evan, WB #12.