the acro 280 is a much much hotter wind than the normal speed 280 hence you would need a MUCH smaller prop,..or prefferably a higher gear ratio. 2 minute flights with 220mah cells would indicate over 6 amps which is way too much for those cells. The stock gearbox most places sell with the IFO is a 4.0 ratio, and that motor will pull 8.5 amps with a 9X6 on 7 cells with a 5.0 ratio. If you have a 10X4.7 slowfly prop on it and the 4.0 gearbox,.. it's simply a big mis-match in motor/gearing/prop, probably drawing over 10 amps, which that motor won't handle for long without releasing it's magic smoke, as you've seen . First off, you'll need larger cells to deliver the current for that motor (which is probably burnt up now due to the high current and smoke you noticed). That motor needs the 500AR cells which are a bit large and heavy for an IFO. So,.. a couple choices,..get the proper gearbox with 5.0 or higher ratio, and go down to a 9X6 prop (might be Ok with 10X4.7 if you gear it higher at 5.0), and get some larger cells to handle the current, or,.. get a normal speed280, which will draw about 3.5~4 amps with your present gearing and prop (less power, more duration, but within specs on the motor). The acro 280 is a 4000KV motor, whereas the normal speed 280 is about a 2300KV motor, hence the huge current that burnt up the acro 280 since it was used with too low a gear ratio and/or too large a prop. the 4.0 ratio and 10X4.7 prop are recommended, but with a speed 280,.. so I wouldn't blame hobby lobby unless someone there specifically sold you the acro 280 in place of the normal graupner "speed 280". Yes, the acro is called a "280", but it's a much hotter motor, hence you'd need different gearing/propping/cells.