Does it matter which direction (forward or reverse) or heading (clockwise or counterclockwise)? I just had one that ran great except in reverse headed counterclockwise through a curve, then it would stall into neutral. The tender to engine leads were too stiff and too short exerting force on the tender in curves, plus there was a non-Flyer insulated bushing and rivet on the front truck that prevented the chassis from having enough roll freedom before lifting up the metal wheels which happened to be on the inside rail. By replacing the wires and installing the correct bushing, rivet, and tin washer -- all is good. Runs like the wind now any which way.