New to me.... Lionel 18322 FM running / sound ?

With AC motors and no "cruise control" it's quite normal for that locomotive to slow on tight curves. 

I just noticed... that original postwar  FM's had  the truck wheels in a different  configuration compared to the PWC .. to me it seems so they could add the wheel sensor for the speed pickup..

the newer version has  /  flange / smooth/ flange/    

the original arrangement has   /  flange  / flange / smooth.

Just wondering if the original  FM's  arrangement  ran better on Lionel tubular 031 than the newer (FM ) one... (I have)

Just my observation but any time I see postwar engines they seem to stay at speed going around curves. The newer ones with current pullmor motors definitely slow down on curves. My observation is based on my first Lionel engines from the mid 80’s on. They slow down. Your engine is probably fine.  

romiller49 posted:

Just my observation but any time I see postwar engines they seem to stay at speed going around curves. The newer ones with current pullmor motors definitely slow down on curves. My observation is based on my first Lionel engines from the mid 80’s on. They slow down. Your engine is probably fine.  

If I'm running my 2343 F3s at slow speed (i.e. 30 scale MPH or so) they noticeably slow on any curve less than 072. Even on 072 curves there is a bit of difference in speed between the curve and the straight section. Any locomotive without speed control is going to slow on curves from friction, unless it's blasting around at full speed.