First post, here and I am probably making a mistake, although I did look and could not find what I was after. A bit of back story, When I was alot younger, I had 2 lego train sets (4563 and 4564). I enjoyed these alot. Recently in my life I have found myself in a stable job and having enjoyed my share of lifes delicacies, I have found myself building my old lego sets. After buying some second hand 9v train motors from ebay, I find the train motors at various degrees of life (I.e 2 motors are quite quick, while 2 of the motors are slow). I have a long term plan to build a city and use the spare motors in either doubling up (Ie 2 motors on 4564) or for arguements sake in the tram from set 60097. So basically I would like a guide to renewing/restoring the motors themselves inside the bogie. Sorry for the long winded post, which the answer will inevitaby be right infront of my eyes. Im a competent solderer (isnt that even a word ?) so I am ok to take them apart the Bogie/motor to rewire etc. Is there anyway of changing the motor for a power functions motor (the motor inside the bogie, Im hoping you all know what I mean haha) or can I buy new 9v motors?? Thank you in advanced.