QUOTE: Originally posted by Railroading_Brit I've had the same problem with an N-scale Lifelike E7 and an Athearn HO loco - they seem to be surging rather than running smoothly. I've cleaned both wheels and track and there's no noticable improvement (the Athearn SD40-2 that does this is brand new, only bought it 2 weeks ago). If anyone has any ideas as to how to cure it I'd be interested to hear them - this is the only Athearn loco I have that's ever done this.