We purchased our Bachman chatanooga last year, it ran perfectly then.  After xmas we put it back into it's original box and stored it for this year ( in the shed).  It hasn't been touched since last xmas, however when we took it out to set it up for xmas this year it barely runs.  On initial start sometimes it won't run at all, and then when it goes aroung the corners (we have it set in a basic oval shape) it slows down almost to a complete stop, and then must be helped around the corner.  We cleaned the rails, but it is still happening.  What can we do?