Hi, I have a set of athearn gensis F7 A&B units. The "A" unit works fine, but I find at very slow speeds the "B" unit tends to go normal speed, then slow, then normal, then slow.
This only happens on the lowest speed settings (I'm using DCC). I don't think its anything decoder related. Also this is very regular, it definitely has a cycle to to.
Any ideas? One of the members at my train club suggested the engine just needed to be "broken in" - but I've given it 20 or 30 laps around the modular layout (probably 120' total around). Could this be the issue, or could it be something else.
P.S. I'm scared of taking apart engines, but I did on this one. Made sure none of the decoder and/or wires were touching the flywheels, etc.
Thanks in advance, Scott