I commend your choice as that is a great trainer. A K&B .48 is overkill for that plane. I've seen them fly extremely well with a plain bearing .40. The K&B will easily out pull the OS .46FX and likes larger props also. I suggest you use a slightly large prop with a slightly small pitch to stop over speeding the airframe and allow steeper climbs without stalling. Maybe a 12-5?