I haven't had that problem with these locomotives. I have turnouts from a variety of generations and manufacturers, and some of these have required extensive tuneups to get reliable operation, but my Bachmann 2-6-6-0s and Consolidations all perform reliably. That's right, I said 2-6-6-0s. I shorten the 2-6-6-2s to make Denver & Salt Lake 2-6-6-0s. Of course, shortening the frames, boilers and tenders all void the warranties, but I am willing to accept that in order to get locomotives that are so quintessential to the D&SL. (Note to Bachmann: after the D&RGW took over the D&SL, these were used by the Rio Grande until 1951.) (2nd note to Bachmann: I am aware that attaching a Keep Alive to the original decoder will void my warranty, but I will gladly accept that in order to get smoother operation.)

I want to add a Keep Alive to an N scale Spectrum 2-6-6-2 DCC on board. Where do I attach the wires?

I have a first generation Spectrum N scale 2-8-0 that runs like a Swiss watch on the level and uphill. But going downhill with ten cars and a caboose behind it, it has a very jerky motion that must be a bind because it is in sync with each revolution of the wheels. When I put it on Bachrus rollers or upside down in a cradle, there is no bind. I checked the clearances in the rods and valve gear, and they appear to be OK. The fact that this only happens when going downhill, especially on my steeper (3.85%) grades has me stumped.