Jim,
I must really be getting old. I completely forgot about this discussion from two years ago. I will include a link here for the benefit of the OP.
http://cs.trains.com/ctt/f/95/t/183361.aspx?sort=ASC&pi350=3
Earlier this year, I took down the American Flyer layout that I had set up the year before to make room for expanding my HO scale layout.
But, before I took it down, I noticed that the my American Flyer steamer was running pretty slow once again in forward. I never did service the armature assembly and now I think that this may be the reason for the slow running performance.
Maybe after the holidays, I will set up the American Flyer once again and do some servicing.
Rich