I have a Craftsman Riding mower with a briggs and Stratton 18.5 hp ohv intek plus engine. The engine acts like it is not getting enough fuel. I checked the fuel pump, and it is putting out plenty of fuel. What other things might make the engine run like this?

Hi,
Believe it or not, needing a valve adjustment will do it on the exhaust side since it cannot get out the old exhaust.
Peace,
Clarke