Featherweight Belts 3. Just a note about Featherweights and belts. Some machines run faster than others and this can be partly attributed to the belt. The belt uses some of the motor energy. The trick is to minimize this energy.
Energy is used bending the belt around the pulleys, especially the small diameter motor pulley.
The tighter the belt tension, the more energy comsumed. Ok, so just adjust the belt tension to be as loose as possible and not slip. Another consideration, is the belt itself. The original belts are black rubber, Singer part no. 194144 or 194144-001. The numbers are printed on the back side of the belt, but old belts will have them worn off by the bobbin winder.