With 140mm center-to-center and a 143mm seat, well, I would think the seat wasn't wide enough. It's nice to have 10mm beyond each bone so you're on the actual saddle rather than weightbearing on the edges.

(so, with 140mm center-to-center I'd be looking for 160mm saddle. My measurements are around 180mm and I ride a 210mm saddle)

"Your mileage may vary"