Glad to see this thread come back from the dead. Anyone have an opinion on this plane using an OS .90 2-stroke? Mine has been hanging in the garage unused for several years now, as the YS 1.20 got very problematic. I was given a NIB .90, so have been thinking about an engine transplant. Got to admit, using a 20cc gas is attractive...but so many other projects to throw $ at, and I do have this engine just sitting.....