60 size Saito, it's what I am doing next. I have one with a 46 la, it flies, but the slightest breeze blows it away. A strong running 45 / 46 will cover it, but I am to the point where I am tired of the 2 strokes. I have several of each, and the little bit of extra money outlay for purchase, doesn't compare to the way they run, use less fuel, and a lot less slime on the plane. They don't sound annoying, the engine makes a completely different sound that doesn't remind me of cutting wood. As far as maintenance, I have only had to adjust the valves on one engine in 3 years, and that took a total of 10 minutes. The LT 40 is a great airframe, although I have to say that I have put a lot more time on the Alpha airframe, because of the Magnum 4 stroke on it. It gives right about 20 min. flight time, and just keeps running without any fussing on 10 and 15% fuel.