I have a Evolution .61NT that I got at a flea market a couple of years ago for $40 and it still runs great even though I've planted it HARD twice! I also have a Evo .40 PTS engine that ran fine when I first got it, then the piston swelled or something and it would lock up at TDC. I took it apart and honed out the cylinder a tad and now so far, it seems to run good again. Definatley remove the limiters, and it does take a bit of tweaking to get the low end tuned right for a good idle to WOT transition. Parts are cheap though and easy to get from Horizon Hobby. Oh yeah, they're a lot better than the CRAP MDS engines that Hanger 9 used in their earlier models[:'(]