This is a follow up of the most recent lawn mower find a free Troy Bilt with a 675 series Briggs and Stratton Engine. The owner could not get this to start put a new spark plug in it and then just listed it for free. Cleaned the carburetor and gas tank it barely would run the first start. They had not gapped the spark plug just installed it out of the box. It runs much better but still has a slight miss in the engine. Will continue to work on this to see if we make it run better.