To upgrade to a 50 is a bit expensive, 90 or so for the upgrade kit, 200 for engine and muffler... but you would not likely have any problems with it. The OS 50 tends to run cool, not very tuning sensitive, and makes bags of power. The bad news is it is very thirsty. I go thru a gallon a weekend.

I haven't flown the 37 but they are already becoming a popular upgrade here. After battling with a tt 36 for a couple months, a buddy of mine switched to the OS 37, and it really put a smile on his face. Trouble free right from the start. No substitute for good running engine and properly set up heli. Might be a good idea to have a local heli guy have a look maybe he can come up with something. Not sure of your financial situation, but i would recomend not spending too much time on it if you have reason to belive the enya isn't going to work well for you. Engines are expensive, but a good weekend has a certain value too. i spent a month of weekends on a lemon engine a couple years ago. I will never do that again. 8 days lost in a failed attempt to save 90$.