Please can you help? Unit will in about 5 minutes of running after start up, idle up if AC 120 volt circuit (light bulb) is activated, utilized, used at idle point. Open voltage at welder output terminals is 0 volts at idle, at this point, unless engine speed is raised to about 1800 rpm, and at this point, spark up occurs, output voltage varies between 6 and 18 volts at this point. It has been suggested that capacitor bank is week. It was tested and readings were 80 mfd at 365 volts on all caps.