Small Engine Troubleshooting Problems? Ask a Mechanic Now.
The fuel pump has a vent in it , on the crankcase pulse side. Thi is where the oil will leak from.
Will be caused by too much oil in the crankcase, or the oil being too thin from gas contamination. Is the oil over full or smell of fuel in the oil?
The leak is what you see, but not the cause. Cause is the oil to be pushed into the pulse tube that powers the pump. Line will be coming off the rocker cover or from the crankcase.
The engine has a vent line to the air inlet , before the carburetor. need to check that the vent line is open and breathing! Breather hose may be pinched or collapsed, making the crankcase pressure higher than normal, and pushing oil out the fuel pump vent.