Small Engines (Lawn Mowers, etc.): lawn mower, briggs and stratton, carborater

Question
i have a briggs and stratton 4 hp lawn mower
i have no adjustments for my carborater. it wont idle correctly and puff black smoke and has oil deposits coming through the airline that comes from the block.
any ideas.   also thank you for the last response, i should have been more specific,  could it have a burnt valve?
thanks    robert

Answer
Hi Robert,

I don't remember our last e-mails but to test for a bad valve a compression test should be done.  If it won't idle, a carb cleaning or rebuilding would be the next step.  The air filter and spark plug should be good also.

Good Luck,
Michael