Well, over here in the UK we used to have engine shed for steam locomotives, but now we have MPDS or Motive Power Depots. So I suggest Motive Power means diesel locomotive.

NORTH AMERICAN RAILROADING SPECIALIST MODEL SHOPS
http://www.ukmodelshops.co.uk/retailers/catUSA-Railroading_Specialists

You can fit a decoder in the American 4-4-0 but it needs drastic modification such as cutting the top of the tender off as shown in this guide. http://www.trainbuddy.com/Reference/decoding%20Engines/N440.htm

Don't post on the thread then richg.

It seems very odd to hide yourself when you think of how other company's are in a mad scramble to get Facebook likes.
It's the whole Bachmann website that's not indexed, not just the forum, so if you're searching for products using Google you won't get any results from the Bachmann website.
If you think it's not a big deal, how would you feel if every website did it? You'd never be able to find anything.

Your loco Jerry. Do what you want with it. You're still putting 15v AC through a 12v DC motor. Some of my locos are still running after 43 years. Do you think a motor that has been running on the wrong power source will last that long?

Just because it's allowed doesn't mean it should be done. See NMRA member Mark Gurries page on 'DC Locomotive Damage Risk'.
https://sites.google.com/site/markgurries/home/technical-discussions/dc-loco-on-dcc/dc-locomotive-damage-risk

It doesn't make sense to burn out all the motors in your locos, that's why more advanced systems don't allow it to be done.
If you want to run DC locos, unplug your DCC controller from the track and plug in a DC controller.

It's about time this feature of being able to run one analogue loco on a DCC system was removed. It's very bad for your motors. I don't know of any of the specialist DCC manufacturers who allow this on their controllers.
On every DCC comparison site I've seen they say to avoid the train set manufacturers, when it comes to DCC controllers, because of things such as this.

255 is an error message saying the CV can't be read, which I would suggest in this case that the decoder doesn't support CVs 5 and 6.
Without CV5 the maximum speed can't be altered. There is no algorithm as it's a hardware problem.
Sounds like a mechanical problem. I'd take it back to the shop for a replacement.

Use the 'Read type from Decoder' function of Decoder Pro to find out what model the decoder is, and using that information find out if the decoder supports CV5. If it doesn't then you won't be able to alter the maximum speed.
If you're not altering CVs with Decoder Pro why did you say you've 'messed around' with CV2?

CV5 controls maximum speed, not CV2.

Erm, you divide by 160 for N Scale.

Six feet between the outer edges of the rails. It started off as 4'8" until the first railway passenger was killed in 1830.
See http://myweb.tiscali.co.uk/gansg/2-track/02track3.htm

Minimum distance in the UK is 6'.