Model number 46539 3500/4000 Champion Generator runs for 20 min and dies, it will start for about 20 seconds then die again. Carb is good, ran it through a sonic cleaner. Put spark tester on it and it drops spark and dies. By passed the oil level sensor and still does it. I regapped the coil and still no go. There is some type of computer board before it sends power to the coil. I can't find it on the champion power tools parts page.