RE: witch Engine should I use?
91 fx would be as good of a choice as the 75 ax (or better),, The Saito would be a better choice then the YS if wieght matters, the Saito 100 is much lighter
On a Mojo 60 the Saito 100 is the Cats meow, The YS makes the plane act heavy IMO, surprized me I thought the YS would be great, but I changed back to the Saito.