If you have already read my S-CAB conversion article about this engine, you will have noticed that the stock American Models engines came with a Mabuchi RS-385SH motor. After online research I discovered that these are motors used in hairdryers. In other words, they get up to speed really quickly. What I discovered was that at speed-step "1", the engine moved at a reasonable speed (not "switching" kind of speed, but perhaps slow for a road-going engine). At speed-step "2" it was significantly faster. Beyond that, it ran at toy-train speeds! I played around with the adjustable CVs of the decoder, but nothing really helped. After e-mailing with Neil Stanton about my situation, he recommended that I consider replacing the motor. Dave, of NWSL, reached the same conclusion. I stripped my engine of all of its S-CAB components, and sent Dave the bare frame with old motor. It took a couple of months, but I eventually got my frame back as shown in these photos.
Dave installed the NWSL 20x32 motor in it (part #2032D-9), which has the double shafts. The motor is rated at 9,500rpm at full voltage. Dave highly recommended installing two flywheels, but I opted for only one, because I need the space above the rear area for the S-CAB double battery. The flywheel fits the 2mm motor shafts, and has an 18mm diameter and is 11mm wide (part #406-6). The universal connectors were two that Dave needed to custom-make for this engine (part #492-6). Parts were $39, and labor was about $50. If I were to do another one like this, I would just do it myself and save the labor cost. Shipping was $12.95. I think Dave used his HO-scale NWSL "Re-power KIT w/2032 motor". The installation was done neatly, and a quick test with a 9V battery proved that it worked. I now need to re-install the S-CAB system and then I'll report on whether or not it improved the performance of this engine. Note: upon later discussions with Neil Stanton, he thinks that flywheels are now no longer necessary if you are going to power your locomotive with batteries. So, you can consider that option.