Things to think about.
1. What is the KV of your motor? (kv x volts = rpm) Example: 2000kv x 14.4volts = 28,800rpm (good rpm) You are looking for an rpm roughly 25k - 35k range.Lower KV on amotoror get a lower voltage battery and you have less rpm's.
2. What is the voltage battery you are running? 2s? 3s?
3. How do you know your batteries are charged? Voltmeter? Have seen people think they are charged up when they are not.
4. Specifically what esc are you using? Did you set the endpoints when you installed it?
5. What prop do you have on there? Take a hard look at the prop, any damage or nicks?
6.Did you wire the motor backwards and then set forward to reverse on the throttle. You can switch any two wires from the esc to the motor and it will change the direction of the rotation. Ihave seen people get this backwards and then attempt to corrected it by switching the throttle on the radio to reverse. So ...crazy as it seems you pull the trigger to go forward and you do, but you are really in reverse as far as the esc is concernedand get a fraction of the power.


Hope thishelps you out..