I am building a Hangar 9 - T34 Mentor and am trying to select an engine. I have a SuperTigre .51 that I was going to put in it, but have begun toying with the idea of running a four stroke. If I run the four stroke it will either be a Saito 82 Golden Knight AAC w/Muffler or a comparable Y.S. four stroke. Two questions: (1) What do you think about a four stroke instead of a two stroke? (2) Is there a comparable Y.S. engine?