I have an evolution 61nt on my four star 60. It started great the first time I test ran it. When I went to test fly my plane, It wouldn't start. It seems the glow plug was bad. I replaced the plug and it started right up. I have had no other problems since. It idles incredibly well!! And revs up real nice. A very reliable engine! It dosn't surprise me, I have an evo 40 and an evo 46 and they also perform just as advertised!