Trying to MU two Spectrum 2-8-0's

[tomgschilling]

I recently purchased two 2-8-0's with the factory DCC decoder installed.  I would like to MU them but one runs very fast and the other, you guessed it, very slow.  I've messed around with CV2 and then CV's 3 and 4.  Nothing works.  At this point, I don't know whether the difference in speeds is due to the locos or the decoder.  Both locos run very smoothly on their own.  Am I missing something or is there no way to match the speeds up without installing a more capable decoder?  Thanks.   ...Tom

[skipgear]

CV 3 and 4 are acceleration and deceleration rate. They don't have anything to do with speed, only how long it takes them to get up to speed.

CV2 is minimum speed, if the loco's do not start at the same thottle setting, this can be used to match them, but again, it does not affect top speed.

First thing before trying to do any speed match is let the loco's run for an hour or more to break them in and allow any binding mechanism to wear in. If they are still pretty far apart, take the slower loco and look for screws that are too tight or binding in the mechanism. The one problem with the DCC decoders is that they can hide binding issues because of the pulse power that they create for the motor.

The first thing to check is the screws on holding on the gear cover plate on the bottom of the loco.