Key ATSF 4-8-4 Question

[Cajonpassfan]

All of Loren's suggestions are right on; brass requires TLC and then some. The Hallmark Northerns can also be much improved by remotoring as the original motors have very little torque. I used 14 and 16" mm Sagami's and a lot of additional weight. They run great. The 16mm is extremely tight...
Otto K.

[Loren Perry]

Although all the methods I listed worked for me, it isn't necessary to do all of this very often. Once I have an engine tuned up, it'll run trouble-free for many months with little more than an occasional wheel cleaning. And on my ATSF 2-10-4, I had to replace the motor which eventually burned out under heavy load pulling. The tiny little stock motor was really too small for that engine. I ended up installing a Sagami motor I bought from Northwest Short Line. Even though the Sagami suffers from "cogging" at low RPM's, it smooths out at speeds above 10 smph or so. Its larger diameter and superior construction make it a very good match for this big loco. It's a tight fit because the cab is sealed off from the boiler/firebox by a solid brass bulkhead (backhead) that I didn't want to cut away. So any replacement motor can't be too long.

[peteski]

Sadly, it looks like Atlas finally took down the forum.
Too bad, because you could still sign in and look at stuff, like peoples names.
Don't know if the PM stuff still worked as late as July.  (Last time I was there.)

Excellent idea Fred!  Forum is still up. I just visited and I both emailed and PMd EBIT asking to join us on the Railwire. Let's hope he gets the messages.

[Cajonpassfan]

Although all the methods I listed worked for me, it isn't necessary to do all of this very often. Once I have an engine tuned up, it'll run trouble-free for many months with little more than an occasional wheel cleaning. And on my ATSF 2-10-4, I had to replace the motor which eventually burned out under heavy load pulling. The tiny little stock motor was really too small for that engine. I ended up installing a Sagami motor I bought from Northwest Short Line. Even though the Sagami suffers from "cogging" at low RPM's, it smooths out at speeds above 10 smph or so. Its larger diameter and superior construction make it a very good match for this big loco. It's a tight fit because the cab is sealed off from the boiler/firebox by a solid brass bulkhead (backhead) that I didn't want to cut away. So any replacement motor can't be too long.

Loren, what size Sagami's did you end up using? I don't have a slow speed "cogging" problem on my 14 and 16 mm motors.....did you use the 12mm? I'd like to know because I have a 12mm in mind for a switcher project and don't want to bother if it ends up cogging at switching speeds....too much work for a mediocre loco...
Thanks, and regards, Otto K.