nikki carb prolems briggs & stratton motor 18ohv

My mower won't start and I need to know how the "Operator Presence Control Bar" functions. At the end of the OPCB cable is a wire that runs to the armature. I assume that when the OPCB is in it's "not-run" position there should be continuity from this wire to ground. I also assume that when I pull the OPCB that there should no longer be continuity between ground and the wire. Is this correct? With my VOM I have continuity between this wire and ground all the time. When I pull the wire off of the armature then my assumptions above work. I disconnected the plug wire and had same results so assume I do not have a shorted plug wire, sparkplug, or the wire running from the armature to the OPCB. Could the armature be shorted internally?

A customer dropped off a Toro Model 20071 with a 2007 serial number. Mower will run on starting fluid but not on its own. I completely cleaned the carburetor, but it wasn't very dirty. I followed the priming instructions carefully and I know gasoline is flowing from the tank to the float bowl, but no further. I have a replacement primer assembly, but the snap ring set up looks like it will be detroyed when it is picked out of there. Am I missing anything here? Does the small diaphagm that is attached to the primer continue to be a key component in moving fuel from the float bowl to the intake valve area?