I have been having this issue for a while and have got no idea what is going on. I have a set of EMAX 1400kv motors, which the datasheet says will provide me with 500g of thrust each when given 8V 9.1A and using a 8x4 prop. I have a 11.1V 1550mAh 3Cell battery(fully charged) and it is only giving me 300g of thrust. Does anyone know why??