Buying and operating old HO brass diesel locomotives can be exciting but the buyer has to be aware that often the mechanism is not as highly engineered as the body shell. There are manufacturers who make excellent drive systems out there such as Overland and there are others that no matter what you do to them they should remain just static display models. For those handy with tools I offer these practical tips to help you make that older diesel operational: 1) Replace the open frame motor with a new precision can motor from A-Line, NWSL, or Sagami.  Micro Mark and NWSL have excellent flywheels and universals to assist you in making the conversion work. 2) Use silicone adhesive to install the motor and, if you prefer DCC operation, a short section of Plastruct 3/4" beam can become an effective cradle, sound absorber,  and electrical isolator between the new motor and metal chassis. 3) Clean the mechanism thoroughly and apply pearldrops or other mild abrasive tooth polish to the gearbox to help deburr the machined parts. Run for a half hour in each direction, reclean,  and apply proper lubricant for smooth operation.4) Modifications to existing universals can be done by cutting the original shaft in half and splicing in a section of brass tubing to either shorten or lengthen the driveshaft to fit the new motor installation. Secure all pieces with superglue. 5) Old TV antennas are a good source of telescoping brass tubing useful for splicing driveshafts, encasing headlights, or even exhaust stack material. 6) Additional pickup wires to the electrically insulated wheelsets will reduce stalling on hood units and switcchers whereas Miniatronics 2 pin connectors linking cab units through the rear porthole windows provide similar results for F units and ALCO's. Write me for details if you need help - it's free via e-mail.  Akrontrains