Update,
OK got ahold of lincoln and they walked me through it. Wasn't hard at all. And Scott, it was located in the back as you stated. Thanks for all the help. It is working like a champ. Again I love this forum.
Bruce
I have a Lincoln 125 as well. It did not have a gas kit. A friend gave me another 125 that had quit working that he couldn't fix. It has a gas kit. I took all the parts off his and installed them on mine, but one of the wires from the solenoid was loose and had a piece of black tape over it. I assume it plugs into the circuit board under where the other wire from the solenoid plugs in, but I wanted to be sure.