Question about GP 7s and Lionel Postwar locomotive speeds

[Prairietype]

I have predominately postwar locomotives.  All seem to run differently.

One of the slowest runners is a Burlington 2328, which at best only seems to run about 75-80% as fast as my 2363.  It pulls ok for a single motor unit.  What I don't understand is the significant difference in top speed, as compared.

In fact I also have several 200 series Alco FAs, more than a few of which are rebuilt from junk.  Some of these run faster than the higher pedigree F3's and GPs.

Does anyone on the forum know why there is such wide variations in running performance?  One thing I'll mention up front is that rollers are good, and oiled; the lomotives have good or new brushes; the armatures top plates are non-gunked, bare metal electrical contact for essential grounding is correct;  as are the gearing and wheels.

Is there any possibility that motors just weaken over time, and if so how do you fix such a problem; a new armature?

Thanks for any information. I'm sure this will be interest to many, and I'm sure others have had similar problems.

 

[phillyreading]

Not all Lionel postwar engines ran the same, if you have cleaned and lubed everything correctly, according to Lionel instructions, there isn't much else to do. One other thing to look at is the brush tension or springs that help the brushes to hold proper tension against the armmature, if the springs are weak, you may see a small yellow spark inside the armature area as the motor turns.

[wjstix]

FWIW, I'm not sure I would agree with the idea that the "higher pedigreed" an engine is, the faster it should go. It's pretty easy to make a cheap engine that will go 200 MPH down the track. Generally engines with better motors and such will be able to maintain a smoother / slower constant speed than a cheaper engine.

[Mr. S.]

Sometimes the motor and/or power truck is at the end of its life.  And remember they were toys, although generally quality toys for much of the postwar period...some just ran better than others.

You can try switching out for a new motor and/or power truck.  I've compared motors mounted in their power trucks on the workbench, and installed the one that ran the best or the best-running combination of motor with power truck.  Or in the case of steamer spur gear motors, whichever one ran best on the bench.

Sometimes you can get lucky...a diesel "junker" may have a good motor in it with not so many hours, I always looked for original pickup rollers that looked barely worn.  I re-motored maybe five this way when all else failed with the existing motor, and they turned into good runners.

Just a thought, good luck.