I have a set of NJI Brass New Haven "Washboard" commuter coaches which I purchased at least a decade ago. While the set is attractive (the terrible decals notwithstanding), the powered chassis could only be described as "horrible" at best. It would not stay on the track, even on a tangent section. The trucks would simply jump the rails, every time. And the noise generated was also off the charts.
Not too long ago, when Ron Bearden was soliciting the attention of persons with brass locomotives that had Kumata drives, I informed him that I owned this set and would appreciate some assistance in trying to figure out why the powered car ran so poorly. He suggested that I forward the unit to him for evaluation. He had already refurbished another modeler's Washboard chassis with great success and would be happy to see what he could do with mine.
I sent the ailing model to Ron. What I received back was a model that is equal in performance to any state-of-the-art example on the market today. It creeps from tie to tie at achingly low speeds without the slightest hesitation or cogging. Ron informed me that it will run at 3/4 of full throttle for 1/2 hour with virtually no excessive heat buildup, but I will not subject it to that test.
Ron is hoping that some more exposure to his efforts will net him contact with the Kumata-driven models that he still needs to consider his project a total success. Dealing with Ron has been a gratifying experience; he is very generous with his time and his considerable knowledge. Willie R.