Okay, I've checked the grounds and cleaned them. Pulled the wire off the small spade terminal at the coil and checked it and cleaned it. Seems fine with good tension. I replaced the spark plug yesterday with an original plug from Cummins/Onan dealer. I pulled the 12 terminal plug apart that goes to (I think) the voltage regulator. It looked fine but spread the terminals slightly to increase tension. It has been running for 20 minutes and started the same old thing. It's like it gets hot and losses ignition for a second and then picks it up and will run for a few minutes before it does it again. Sometimes it will cut out and backfire and then MAY die.
ANY ideas? I hate to just start throwing parts at it and the Cummins/Onan dealer doesn't have a clue. They want me to pull the entire unit out and bring it to them. Plus they are a hundred miles away. I would really like to figure this out.
Thanks