I rebuilt a couple of these 1666 locos, and put a lot of time into customizing one with a "Crescent-ish" Lionel Lines paint scheme.
Finally pulled it out to run on dad's layout after a long time in storage after my move from Florida. And HOLY **** this thing is a rocket when being run by my dad's KW.
It's actually a problem, because it goes from zero to almost too fast by the time I get to 9 volts or so. To run it slow enough that it won't fly off the rails, I have to keep it at like 7 volts (and that's still pretty fast). Problem is that over dirty or rough sections of track, where there's a slight voltage drop, the E unit cycles.
Is this common with the open frame 1666 PW motor? Is there a reasonable way to slow it down so it's easier to run and easier to maintain voltage to the E unit coil?