Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hi, my name is***** will be assisting you.
What engine do you have on this machine? Can you provide the model and serial number from the frame of the machine?
There are several reasons that this could happen. If the crankcase becomes overfilled with oil, a blown head gasket, broken ring, air leak around the engine gaskets or seals that is allowing the crankcase to become pressurized. The easiest things to check are oil level, oil leaks from any part of the engine. Then you would do a compression check on each cylinder if more than one to see what the compression is. Then a cylinder leak down test to check integrity of the rings and valves.