Pull the fuel line. They stop every time when you do that.
I value my fingers a little too much to be doing that.
Actually, I can stop the motor by grabbing the spinner with my fingers, but that seems a little dangerous, too.
If it's a real issue to you, remove the carb, clean the mounting area carefully to remove oil residue, and then
put a FINE BEAD of RTV on the seat. Let it skin over for a few minutes then reassemble. You should be fine.
I'll try that, although it does have a gasket there already, and I've made sure it's clean and the carb is tight. Perhaps it does still leak a little. We'll see ...
Phil