Well, I did as suggested and at first it didn't seem to make a difference. It would like lurch forward and stop.  Then I got frustrated  and set the throttle at full speed and switched between forward and reverse (running on DC). After 5 or 6 times of this it took off and hasn't stopped. It acted like something was bound up, but is working fine now.

Thanks for the help guys! I'm just starting to get into model railroading and this is my first locomotive.

I finally got time today (I bought it 2 weeks ago) to put some track together for her maiden voyage. After about eight runs around the track it started derailing. I noticed the middle 2 axles no longer have any side movement like they did in the begining. If I let it be for a while they would loosen up a little and it would stay on the track for a round or two. It's like they get hot and want to freeze up.

Anyone know of this problem and if there's an easy fix?

Thanks