Okay ... silly question from a newbie train guy ... I recently bought the Dewitt Clinton train set and after a few days of use, it's begun this jerky stop/start action (it's mostly stopped now) .   I suspect it may need lubrication, but not quite sure where to apply.   I read the documentation that came with the train set and it's a bit vague where to apply the EZ Lube.   This thing is so small and delicate, I don't want to ruin it.  Any help would be appreciated.