One of the HO items in my collection is a brass Korean built Pacific Fast Mail Northern Pacific S-4 4-6-0 Steam engine tender. The unit was factory painted with a number of nice details. It has an open frame motor.
The objective was to establish the performance of the engine prior to sale. Unfortunately, the motor coupling with the drive was sheared off. That was easily replaced. The engine ran during the warm up running. It seemed sluggish, and the measured speed at 12 volts DC was under 30 SMPH. The current draw was around 0.7 Amps. This was with no external load on a level grade. It seems that there is too much resistance in the mechanical drive. During this warm up running , the engine developed a short and ceased running.
The challenge was to find the reason for the short and eliminate the bind in the drive to improve the EO speed and reduce the current draw.
what happened is that the headlight circuit had some bare junction points that touched the brass boiler. This led to the short. The solution was as simple as covering those bare spots. While apart, the loco was lubricated on all of the bearings & gears.
Even at that the performance was disappointing. I show more specifics later.
