The original question was using a motor to drive a generator. However....
Most electric motors are on the order of 90-95% efficient. There is nothing to be gained by trying to squeeze an extra percent or two out of them unless the motor is extremely large. And I suspect that these motors are not well suited for use in air conditioners, otherwise they would already be in use.
And like chroot said, I suspect you are still unaware of the how both electrical and mechanical power work. For example, amperage isn't power either (from your original question). Electrical power is v*a - so if your voltage is higer, your power is too.
Googling the efficiency of these motors, it looks like they are from 75-85% efficient, though most of what I saw was for RC plan motors - scaling them up may
improve the efficiency. In general, though, A/C motors are more efficient than DC motors.