In the Fall 1973 Train Collectors Quarterly, there is an article entitled "Care and Feeding of Toy Train Motors." In it, the author wrote about the induction motor used in the Western Coil Zephyr. They stated the "Motor is a rather poor motor for this kind of service. It has a poor starting torque and its RPM is limited by the line frequency (measured in cycles per second)..." They went on to explain "the speed of this motor is governed by the frequency of the line supply coming into your home" and after the motor reached its maximum RPM "you can pour on all extra voltage you want and...you will not speed up this motor although you will probably succeed in burning it out."
The Instructions for the Western Coil Zephyr state "Trains operate normally at 12 volts. Do not use over 18 volts or motor may heat excessively. For continuous operation, 10 volts should be sufficient." My advice would be to keep all moving parts well lubricated and operate the train at a minimum acceptable voltage.
