I have an old electric color wheel with 4 rpm motor that I am using for this year's Christmas display. It has not been operated in decades, and during its first use last night the turning wheel would occasionally slow with a jerky pause, and even change direction at times. The frequency seemed to increase after it had been running for a few hours.
Looking for suggestions or help on what I could do to fix it. It was well-kept, still looks brand new, and the motor does not appear to be dusty or dirty---it was stored in a box. What kind of maintenance do these devices require?