Small Engines (Lawn Mowers, etc.): carb, briggs gas in oil

Question
2 year old troybuilt pony,17.5 b&s. gas all leaked out to the oil.how? and why?mowed one time. had half tank of gass left. two days later gas was gone ,would  start but not run. drained oil ,full of gas.

Answer
This is quite common on certain Briggs engines.  The float is sticking or the needle isn't seating properly.  It's such a common problem that when we do any maintenance on the Intek engines, we install fuel shut-off valves in the fuel line.  What you'll need to do is pull the carburetor apart and give it a good cleaning and then install a new needle or needle and seat depending on which carb you have.  Also check that the float isn't leaking and sits level when installed.  If you can get me the model, type and code numbers from the engine I can get you the part numbers you need.  Thanks, PK.