We recently picked up a used Williams Amtrak Genesis at a train show. When we try to run it, it seems like it has trouble getting started and then even keeping going. The power seems strong, but it is like it struggles to get the wheels moving and then keeping them moving. I am not sure how long this engine had been in the box, and it might have been sitting for a while. Do you think there is a chance that we should grease the gears in the trucks? If so, what should we use? Is WD40 ok? Thanks for any help. This is for my 6 year old and he is having a hard time with why he can't run it. Thanks,