No, this is the kit. I think I may just use the .46 2-stroke and save the .52 for another plane. Like Ho2zoo said, I might want the extra umph. I'll fire up the 2-stroke on the engine stand and see if I can stand the sound of the high revving 2-stroke. If it grates on me too much [:@] , I'll go with the 4-stroke and just swallow the fact that it will need a little more tail weight.