Just wrote the following in another posting. Sounds like you have gas in the crankcase. Pull the dipstick and see if it is overfilled and/or smells like gas. It so do the following.

Welcome to the new world of ethanol enhanced fuel. Your float needle and seat will need to be replaced. This is a constant battle all home owners and service tech's are fighting. Today's ethanol fuels are causing the needles to not set properly and the fuel does not shut off the fuel in the carb, and the fuel goes everywhere. In your case it filled the crankcase. After you replace the needle and seat you will also have to change the oil. We suggest to all our customers to use high octane non ethanol fuel in all there small engines to try to stop this problem. Good Luck, should be a simple but unnecessary fix.