I'm planning on building a GP SuperSportster 60 this fall/winter... and I'm planning on hanging a Saito 100 on the front of it... I'm predicting that the way it handles the SS will determine my real feelings for Four Stroke engines... With the SS's, I started with a 20, then built a 40 and flew it forever, until a failed crystal brought it down (I've still got it though, and it *might* be repairable, but I don't know if it would ever be the same again...) and now I'm going to build the 60... I have high hopes! The 60 will be the first 4 stroke powered one... and my first 4 stroke powered airplane that I built. If the Saito will make it do (probably after some considerable propeller experimentation) what I know my OS 61SF or SuperTigres will do with it... I'll be happy.