You will need the motors Technical data. This data is found on the motor label and will list the Volts, Hertz and Amps. Other data listed may be the Bay Motor part number... shown as 5A14_-_ (i.e. 5A140-1) The manufacturers part number which the motor is for may be listed at the bottom of the label.
You should first try to contact the manufacturer of the unit the motor was in. Typically the manufacturer will have Customer Service or a Parts Department with a replacement readily available.