I just purchased NIBox AEC 57 Lionel switcher from 1998 that appears to have never been run. I oiled all pivot points, greased the gears and cleaned the wheels. It ran a little sluggish so I put 2 drops of oil into the armature and it ran much better. I am still seeing a lot of sparks by the pickup rollers as I run the engine. Is this normal? What causes this? I have an old 44 Lionel missile engine that also has a lot of sparking as I run the engine. Any thoughts?.....Rich