Did you ever find the problem? It is an awsome engine and very seldom blow head gaskets. Dixie Chopper quit using Generac engines around 2014 due to the fact they started dropping exhaust valves. While trying to meet EPA emission standards instead of revamping the engine to meet the standards they just kept leaning the carbs. This made them run too hot and crystalize the exhaust valve and pop the heads off. They don't usally use oil. Have seen them with thousands of hours on them and they still don't use oil. I have seen them blow a pan gasket now and then.