I have a simplicity serger model SL850 and my throttle pedal has the end chopped off. Can you tell me what pins on the machine need to make this thing work properly. Voltage specs and throttle pedal wiring maybe? Thank you.

SOURCE: mine is a simplicity 804 easy lock

Your knives may be blunt and need sharpening or replacement.

Check also if the knives are aligned properly. Remove the material and turn the handwheel slowly. The knives should pass each over like a pair of scissors and there should not be any cap between the blades.

If everything seems to be okay and it still does noet cut tne material, replacement is the only option.

SOURCE: A MANUEL FOR A SIMPLICITY SEWING MACHINE MODEL 237

Here is the direct link:
http://www.simplicityhomecare.com/manuals/

SOURCE: Simplicity Serger SL370 - Motor runs but it doesn't sew

Years ago I had the same problem with a sewing machine. Took it to a repair shop which cost me $25.00 for the fix. Asked the repairman what he did and was told that he exposed the bottom of the machine and sprayed the entire area twice with wd-40.

SOURCE: I live overseas, and brought this sewing machine

its not transformer or machine problem at all.all the connections are also proper.its the power issue the required power to the machine is not getting from the electric outlet.just call the local electrician and check out the power supply voltage from the electric outlet.and power required to the machine which will be listed on the machine.if more power is required he will connect the over power IC and get the machine work.if less power is required he will connect the RESISTOR and lower the power to the machine and make it work.

SOURCE: threading instruction for model #1220 simplicity

http://www.sewingstyle.com/Simplicity-Sewing-Manuals.htmlnot
not sure if you have the manual, try this site for a manual,