Glad the problem was resolved but it's odd for a new motor to have those problems. The 110/115 220/230 differences mean nothing and wouldn't cause a problem. FYI there are no brushes in these motors. Brushes are unsed in AC/DC motors such as found in shop-vacs, vacuum cleaners, blenders, electric drills and especially those devices where speed control is needed. Won't go into details as to why but when a motor wired for 240 is run on 120 it will slow down when under load. No load it will run almost at full speed.
Al