A machine has: an outer member; an inner member mounted for rotation about an axis relative to the outer member; and a seal system. The seal system has: a seal housing mounted to the outer member; one or more seal rings held by the seal housing and having an inner diameter surface; and a seal runner mounted to the inner member and having a first outer diameter surface portion contacting or facing the inner diameter surface of the one or more seal rings. The seal runner has a circumferential array of mounting features. One or more weights are mounted to one or more of the mounting features.