I agree with Lee's assessment after looking closely at the pictures. Also, I have a number of Atlas locomotives (4/6 axles) which I use on my shelf layout and if it's been greater than a month since you last operated them it'll help if you set them up to run continuously in forward/reverse for at least 20-30 minutes each way to help "break in" their motors once again. After I do that they run very well over all my tracks vs. before when it's very halty and stalls frequently despite cleaning the wheels. Interestingly my kato engines (NW2's and six axles) never need this to work perfectly!
Hope this helps,
Erik