So another update - the engine still runs on after I turn the ignition off at the switch, so I have to give full choke to shut her down. I checked the fuel solenoid ground at the carb, and that shows continuity with the ground terminal at the battery negative, so good ground there. Maybe the switch I have installed is not the correct one and I need to find the right one?
A few days later, I parked the PT for about 15 minutes after an hour of use, and when I went back she wouldn't start. I waited, thinking she was a bit hot and would cool down. 30 minutes later, I tried cranking and the cylinders were frozen. Pulled the plugs and carb, and I could see gas in both places, the cylinders and intake were full of gas. I assumed the float needle was stuck. I did a quick disassembly of the carb to clean the float needle and seat, and clean the fuel shutoff solenoid. I also cranked the engine with the plugs removed to spit out a lot of gas. Put her all back together and she fired, but with much more choke than usual. In fact, she only runs with about 3/4 choke now, any less and it sputters or dies. She still won't shut off with the key as well. I think I need a carb rebuild kit. I also washed the machine, changed the engine oil and filter and the hydro filter just prior to all of this, but I doubt that's had an impact on what I suspect is a carb problem.
My 425 is an older one, I suspect. It has the Kohler Command Pro 25 with all of the pumps mounted to the front of the engine. It has a steel gas tank built into the lid. Here are my questions:
Does anyone know what carb rebuild kit I need?
Does anyone know what ignition switch I need? (they all look the same to me, so the one I put in might not be grounded right, making it run on)
Does anyone think I am way off target and have other ideas?
Thanks!