Scooter elétrica upgrade

hello, how are you? any technician could help me, I have an electric scooter of 800watts 48 volts with a controller motor 22 amps, I upgraded putting another 1 motor of 800 and controller 22 amperes, the scooter got 2 motors 800w 2 controllers each 22 amps added to the 2 controllers 44 amps, I upgraded the batteries to 17s 72 volts… The scooter was very strong, it reaches a speed of 75km/h but the engine does not heat up nor the controller would like to take more power, but when I increase the amperage out of control for 25 amps each the motor loses synchronism with the controller and makes that ugly noise only at the output after it is quiet, my motor does not have a rall sensor and neither do the controllers, how could I increase the amperage without losing the motor synchrony with the controller ? my battery is 17s 72 volts 23 amps.