If it is running at full speed it is the capacitor in the unit situated in what would normaly be the accessory box that needs replacing.
You can take it out and dump it if you cannot obtain a replacement but may get iterferance on your radio.The other alternative would be to buy a replacement motor and foot control
Vulcan
July 2012
Undo the control and take out the little suppressor and discard it and it will work fine
ken
July 2012
I can answer this question...
How can I fix the knee operated clutch mechanism on my singer 201K?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix sewing machines.