[MrFlippant]

honestly, that surprises me. I know the Mosler is low, but Sport track has flush rails, so it shouldn't be dragging except where joints are not smooth.
I built by P68 from the kit, but the chassis was already together and running perfectly out of the box. All I had to do was lube the bushings and such. I never had to tweak anything to get good performance.

 

[MrFlippant]

The pulsing is a byproduct of how the APB does analog. The pulsing is noticeable at different throttle levels for different motors. It's something to do with the PCM delivered alternately to the two slots, we think. This was something I noticed a while back, and Sean (HankScorpio) and others helped narrow it down. If you put a 9v battery to the braids, it will be smooth like butter.