x speed motor mod

[Hudson5150]

I installed the xspeed motor in my xmod. On first installation I matched the positive and negative wires to the xspeed motor in the same place the wires are on the xspeed motor out of the package. Once installed the car went in reverse when I pulled the trigger on the control and then forward when I applied the brakes. I just reversed the wires on the motor and now it works fine. Now (after the wires have been switched) when I go in reverse (the origional forward for the xspeed) the car moves faster than when I go forward. I think this is because the motor is running backwards as to the way it was meant to run. Any ideas on how I can solve this? Any way I can get the motor to run in the direction is was meant to run?