2-10-2 Lurching at low speed

[UP Mike 2499]

I have a 2-10-2 I recently bought and it is lurching at low speeds. It is barely noticable, but I would like to get it fixed. I checked the wheels, they check out good. I lubed averythnig, not too much, not too little. Is it just that it needs to run for a while? Does anyone else have this problem? Could it be the start of something bad? All comments and suggestions appreciated.

[full maxx]

for break in run it both direction for about 15-20 minutes at half throttle with some stopping along the way...