Mc727Fly,

Are you installing that BP-21 outrunner on the stock Rx/ESC? I was told that it would not work with the stock electronics. I have a 3-cell Lipo and am on my 2nd 370 motor. You will not be disappointed with the performance there...however, be careful to throttle up slowly, and grease your propeller shaft. The plastic gear setup really doesn't seem to be able to handle it, and if you snap the throttle up too fast, you could strip the main gear. I am looking for a direct-drive prop configuration, no gear, with a suitable motor. Let me know if what you're trying works out

Thanks.