675/2025 motor runs slowly

did you oil both ends of the shaft? try running just the motor without any rods(in case one is bent,drivers out of quarter)are the drivers running true(no bent wheels/axels)how are the wires? no shorts? does it run slowly in both directions?

Drivers seem to be O.K. Running true.  Can't see any shorts or wire problems.  Runs slow in both forward and backward modes.  Will try to oil armature axle, but can't see how the oil could get in there.  It looks so tight.   Ed

do the drivers move freely?

Yes, the drivers run freely.  Am now in the process of cleaning the armature commutator, and the brush holder.  Order new brushses on ebay.  Keeping my fingers crossed.  Ed

Also, what to use to lubricate the armature shaft.  Some say use 5w-20 or 30 motor oil.  Others say Lucas oil Red n Tacky no. 2. which seems to be a grease?   Ed

lots of opinions on that. personally I save the quart bottles of 10w30/40 motor oil. always some left, and I fill up my little train bottle. been doing this for 20+ years.

It's my impression that grease should not be used on a porous bearing surface. Your locomotive probably has the armature shaft turning in an unbushed hole in the brushplate and either a bearing mounted on a metal plate or a cast bearing plate on the other end.
I would use a light grease on the brush plate side. I typically use Labelle 106, sometimes the Lucas oil Red n Tacky.

I would use an oil on the other end.

Thanks, guys, for the info. I'm learning a lot.  Ed

Now what did I do?  I cleaned the commutator, brush tubes, new brushes. Greased the shafts with Labell 106. Connected the power leads, Nothing!. All I got was a buzzing sound.  The front lite bulb went on, tho.  But,, I did apply a little Dielectric Connector Protector to the surface of the commutor and brush tubes. Think that might have affected the current flow?  Ed

Di-electric(insulating) grease is not what you want to use if you are trying to improve the connection(s).

An electrical conductive grease like No-Ox-Id is what you want to prevent oxidation and connection break-down, but with brushes, you don't want any grease or lube at all.

Wow,  Thanks, I guess I screwed up with that stuff. Going to bench to clean the stuff off.   Ed

Lots of people have made similar mistakes. There is a relatively easy way to remember: If you imagine that "di-electric" (or "dielectric") is short for "die electricity" I.e., kill electricity, you are unlikely to confuse it with "conduct electricity" as in "conductive grease."

There are some (but relatively few) uses for "conductive grease" in model train performance-enhancement and repair. If conductive grease gets warm, it may ooze out from where it is supposed to be and flow, lava-like, heaven-knows-where. That eventuality might provide more excitement than you bargained for....

Yep, cleaned off the die-electric (like that simile) and motor runs nicely. Whew, what an adventure.  But with you and others giving advice, I came thru to solving my problem.  Thanks, everyone.  Ed

Welcome to the rewarding world of postwar steam Erp. Once you have fixed your first engine, you will be shopping for your next project engine. Enjoy every minute of it.

Could someone comment on the safe (for the motor) ampere limit for an open frame, horizontal shaft prewar-style motor (immediate question is for my Pride Lines City of Denver's power units.  I can supply all the total current needed, but need to weight the units some to get them to pull 2.7 to 3 cars each (ABB with 8 cars) without a lot of wheel slip exiting long 072 curves.  So, I want to use my test track and watch amps at full slip on each unit to be sure I don't hurt the motors, as well as equalizing the weight/current between them as best I can.  I understand advice on the "traditional 0 gauge" forum about limiting motor temperature to about 140 deg F (not too hot to touch for a few seconds), but would like to be a bit more rigorous and know what a useful current limit is.

Thanks, Don