From his first post,
"I'm trying to figure out why my engine seems to take a while to warm up. When I first bring it out, it runs very slowly and then after several runs, it eventually seems to go faster."
Possible something on the engine that frees it self up after it warms up....
Another of his posts,
"Something that I did not mention before was that this problem occurred indoors as well. When I would first start running the train on the starter circle, it would go really slowly and then perk up. This perk up would happen after half a pass around the starter set, so I ignored it. Is there something I should be doing to 'oil' my engine? Does the smoke fluid clean the inside of the engine?"
Possible thick or dry grease made worse with the addition carpet fibers, cat hair, floor stuff, etc., it's surprising what small piece of hair or thread can do wrapped around an axle(s)..?
His last post,
"I found that if I spray wd40 at the wheels, it gets up to speed quickly. This makes me think I've got some sort of gunk or corrosion or bent something. While it has no trouble with a small 20' gondola (LGB Toy Train), it still can't manage to haul my new 40' gondola around the track."
Probably, the WD40 helps the above problems, but doesn't fix it, thats why it it doesn't pull like it used too....