I have a Bachmann Spectrum loco that I want to use on my new layout but when I test ran it, it ran forward with jerky/stalling movements indicating no power being applied. First thought was dirty track so I cleaned it but while a bit of improvement the loco still did not perform well. I then looked at the wheels and pickups and they were filthy so I cleaned them with Metho to get rid of all the rubbish. While I had it apart I cleaned the contacts between the pickups and the internal electronics and greased the drive cog, still not much better. The plated tread coating on the wheels is worn as well (copper showing on one wheel). I then took another loco and ran it over the piece of track and that went quite well forward and backward with no jerkiness at all. I then tried to run the troublesome loco backward and it ran very well but when direction was reversed the jerkiness/stalling returned like there may be a binding issue with the forward direction. Can anybody give me a clue as to where I should look next? NOTE; All my locos including this one have been in storage for over 10 years, so probably are in need of a good service.