I'm not sure about the motor magnet. I don't really know what i'm looking for. Are we talking debris or checking its strength? I will strip it back down later as far as I dare. All the track is modern except possibly a level crossing, which I honestly don't know. I never knew magnadhesion was a thing! Atleast I can rule out the polarity of those axel magnets as an issue. It doesn't derail on the modern track at all. But it doesn't run well at all. At mid power it is very jolty, go, slow down, speed up. At full volts it runs reasonably slowly, the kangarooing stops, but the noise increases.