oil leak

[cobalt123]

Hi
I have a Briggs and Stratton lawn mower
I found at a yard sale its a weed eater 550e 140cc Engine
the problem is the lawn mower is covered in old oil
along the lawn mower body and the engine base
what could the problem be

thank you

 

[bertsmobile1]

Usually the float valve does not shut off the fuel which leaks out & fills up the crankcase
When the owner pulls the starter oil spews out everywhere .
So start with checking the oil level then tossing it out
Remove the fuel tank & clean it out
Slide the carb off over a container of some sort but leave the fuel line connected
Fill the tank with fuel
Come back in 1/2 hour and check for fuel leaking out of the carb.