What Buickanddeere said. That sounds like slobbering which is caused by not properly loading the engine or running it at too cool a temperature. IF not above about 70% load, the rings do not seat properly and crankcase oil finds it's way into the combustion chamber and ultimately out the exhaust. This is common on engines run too cool or started and run from new without applying a significant load to break the rings and cylinder in properly.
If it is on a generator, you need to put 5KW of electrical load on the generator, and get the coolant outlet temp up near 200F and run it this way for a few hours and it should clean up. IF it is running with adequate load and temp, it could be you have a problem with the rings, or it never got completely broke in...