I have never remotored any of the engines you spoke off. But, I do plain remodering some PK 2000 BL 2's. When or if I have suffent funds I plain on using this company.
http://www.alliancelink.com/alp/
I have heard a lot of good things about there Helix Humper motors and they make there own. They don't sell what ever they can get hold of. I like that, they make it and then sell it, no passing the buck. Plus they have tips posted about how to do the install, because they have done them.
I all so agree, make sure it is the motor and not the drive train.
Who made the Big Boy and Challenger and why do you need to remoter?
Cuda Ken
I hate Rust
CB&Q4-8-4FanaticRemotoring a Bachmann 4-8-4
Athearn Big Boy or Challenger in HO?
I used to have a reference to a web site that discussed remotoring and regearing in detail. But I've lost the link. The upshot of the discussion was that in many cases the cause of poor locomotive performance was not the motor, but the drive train. In other cases, it may be both. In relatively few cases (usually older brass) the drive train is good, but the motor alone is the problem.
That said, modern plastic locomotives have their share of quality control issues. One model may be just fine, while the next from the same production batch may have real issues. Consistent quality just isn't there in the Chinese-manufactured plastic locomotives - or least not the 95+% consistency we've grown used to in the larger consumer markets. So unlike US die cast and brass import locomotives, it's difficult to predict how just much improvement a given change is going to make.
Unless the motor itself is making squealing or grinding noises, the best recommendation I can make is to find out the cause of your poor performance. One step is to measure the current draw of the loco before any work begins. This gives you a reference point. If it is high - 0.4 amps or above for a modern plastic loco by itself - you probably have problems that can be fixed.
Remove the motor and power it in your hand. If it is hot, noisy, or vibrates to the point of stinging, the motor needs replacing. Check the current draw with the motor by itself. It should be less than 0.2 amps. If these checks are good, you probably have a pretty good motor, and won't gain a lot by replacing it.
Rolling the mechanism without the motor and worm on a plate glass surface will help you find problems with the mechanism. It should roll freely without any binds whatsoever. Correct and fix until it does.
Regearing may or may not be desirable in conjunction with remotoring. If you have a free-rolling mechanism per the previous paragraph, and you can get the top speed and motor mount you want with the new motor, leave the existing gearbox. OTOH, if you want to mount the new motor where the shafts don't align, or want a different top speed, or the new motor has a considerably different RPM, you may want to regear at the same time.
I realize this is generic and not specific to the models you mention. But the techniques apply across the board, and you find that because of the inconsistency in quality that another person's experiences may not match yours.
my thoughts, your choices
Fred W
Has anyone done this before? Remotoring a Bachmann 4-8-4 or Athearn Big Boy or Challenger in HO? Specifically replacing the motor that is already in their with a Canon DC Motor? I am trying to do one myself and would like to know from other people that have done it how much better it runs with the new motor.