... Could this just be an issue with the decoders that Bachmann uses do you think?
Hey Tony,
I have 5 Bachmann DCC locomotives. All with the original decoders. I have run them with analog DC power and they have all run great. One locomotive, my Chessie/B&O GP38-2 ran flawlessly for more then 100 hours of and on last Christmas with a DC power pack.
All Bachmann DCC equipped locomotives that I know of require about 6-7 volts to begin moving when run with DC power. My Athearn Genesis is the same. This is due to the requirements of the solid state electronic circuitry of the decoder. That will be a noticeably higher setting on your transformer compared to a DC locomotive's start voltage. That part of the problem is normal and not actually a problem.
As I understand Bachmann's decoders the CV's should not come into play other then to enable dual mode. Once it is running with DC power the CVs are not in use, the DC power simply passes through, but I am not certain because I have never seen a schematic of the decoders.
For the second part of the problem I would look for a mechanical problem. It could even be as simple as cleaning and lubrication. As Terry suggested something could be binding.
When ever I am working on a locomotive I begin with a thorough cleaning and lubrication. In my experience that usually solves the problem. If not I have at least eliminated a cheap and simple possible cause.
If you still have a problem watch it closely when it runs. Use a magnifying glass if you need to.
When ever you are working on anything eliminate all the simple possible causes before buying parts. It may save you from buying parts you did not need. Nothing is more frustrating then replacing parts only to find you have the same problem.
When I was learning to be a mechanic the older guys would tell me "be a mechanic, not just a parts changer"