the train makes about four to five rounds then stops. the coal car usually come off the track [back wheels only] then proceeds to make the other cars come off. the tracks seem to fit together good, as I feel no bumps. it is on a hard level surface. any ideas would be appreciated, or do I need to call custmore service? thank you

We just set up the same set and had the same problem. In addition, the wheels keep coming off the track. Also, how does the coal car hook up to the locomotive. There's no eye on the back.