Frage Machine issues

Hello everyone, i installed the performance kit,it works better now, but it doesn't stop when it loses the step, also sometimes but not always when homing it continues to go even when it hits the limit switches? I want to put the old y axis motor that has 1. 8A to X axis, would it help for not losing the steps so often on the x axis?

You can put a motor with a higher rating to the X axis, but it won't help. The current delivered by the motor driver won't change. You'd have to let the driver know that it can deliver more current. I am not aware how the SC boards are designed today ( I have a V1 ), so in the old days a resistor would have to be exchanged. On 3D printers the drivers usually have a potentiometer to adjust the current or newer drivers allow configuration via serial interface.

If your X-axis is loosing steps you should hunt down the problem with an axis moving on high resistance or slow down milling. It's that simple.
Changing the motor is good for nothing as Andreas already pointed out..