I imagine that the pack is way too small - I don't have the specs for that Hobbyzone brushed 480, but if I substitute a standard Graupner can 7.2v 480 you can see that the amp draw is almost 18A. I doubt your 910 pack can deliver much more than 10A. What is the max amp rating for that HobbyZone 480?
Motor: Graupner Speed 480 7.2V (est) #6302; 2450rpm/V; 1.1A no-load; 0.145 Ohms.
Battery: Thunder Power TP2100 (ProLite) (15C); 3 cells; 2100mAh @ 3.7V; 0.018 Ohms/cell.
Speed Control: Castle Creations Sprite 25; 0.0025 Ohms; High rate.
Drive System: Direct Drive Propellers; 10x8 (Pconst=1.69; Tconst=1) geared 3:1 (Eff=95%).
Airframe: Anything you want.
Motor Amps = 17.6
Motor Volts = 10.1
Input (W) = 177.7
Motor RPM = 18513
Prop RPM = 6171
Thrust (oz) = 28.4
PSpd (mph) = 46.8
Isn't the stock pack for that motor only 7-cell NiMh????
Aha, I did some digging and found prop tests for your motor on the AmpAviators site - Using a 3s TP EXtreme 2200 pack and a Power Supply it seems that the stock 10x8 draws about 13A (143W)... there is no way a 3s 910pack will cope with that!
http://www.ampaviators.com/index.php...d=39&Itemid=27