I have a Saito 100 in mine and it's one of the easier flying, more relaxing planes I have. Very well mannered no bad habits at all and very light. I started out with a OS 60 ABC but feel the 4stroke is a much better match. I also have a Lttle Toni with a Jett 90 and its twice as fast and a much cleaner airframe. IMO the Shoestring has too much drag in that large banana fus and too fat a wing to benefit from a powerhouse like the Jett 90, others may disagree but the Saito 100 is perfect for the Shoestring in my book. I like the Shoestring so much I may 2x the size and have a kit cut.
KirkRC