In general 45mm prop and 24V jumper will result in a lot of noise and the pump can burn out if it jams, what will usually happen is the power supply will fail. 45mm prop and 18V uses 28W, the power supply can handle 50W. With 24V it uses 36W, if the prop hits something or sticks, this can go up to 50W+ and cause the power supply to fail, it is a remote possibility the motor would also fail.