With a 32SX-H you're better off babying it a bit at first because it's non-ringed. Use more oil, and don't lean it out if you can help it. Breaking it in on a bench is probably a great idea, considering how rough serious flight in a helli is. Just make sure you supply a load or you're not really breaking it in. I don't know what the proper pitch to use is but a moderate sized propeller makes for a good load.