Those who say we can't tune engines, I think you just got the lucky batch of MDSs. It breaks my heart when I see a newbie at the club with an MDS in his Heli or plane. The club engine experts would spend HOURS trying to start the engine, and when they did start it, they'd spend more hours trying to tune it. They take off, fly for two mins, (if they're lucky!), and either glide down, or for helis, fall. The amount of money wasted with these engines would have bought you a YS before you know it. (I'm the proud owner of a 140L, WOW!!!!)
The new ones are said to have improved, but my advice, DON'T DO IT!
Rob.