msouth,
I have 4 Brillelli engines and each one has been a real nice engine. In the 50cc class they have a awesome engine called a 366GT(60cc) engine. It is only 2 oz heavier than a DA50 and has a lot more power. The engine is very easy to start and is very reliable. The best thing about the Brillelli engines is their customer service after the sell. If you have a question or need some special part made for a particular installation Brillelli is there for you. You will get customer service even on the weekend while you are at the field flying. I know I have called Scott more than once just to ask a question while I was fly-in at the field on a weekend and he help me every time. Don't just look and the engine look at the company you are buying it from. Will they be there for you when you need them most. The Brillelli 366GT engine is only $625.00 complete. They do not sell strip down engines, meaning that you need to buy a muffler and stand-offs after you buy the engine. Give Brillelli a look at
www.brillelli.com