Small Engines (Lawn Mowers, etc.): Briggs and Stratton missing then cutting off., briggs and stratton, magneto

Question
I have a Craftsman mower with a Briggs and Stratton (Model  #287707 Type 1255-E1) engine that is almost 20 years old. Lately it has started to miss, but only after it has been running for over a half hour or so. Today it cut off and I could hear the gas boiling in the air intake. I pulled the air filter off and sure enough the gas was bubbling. I have already replaced the air filter, fuel filter cleaned the carburetor both inside and out and replaced the spark plug. I'm thinking it is getting too much gas, maybe the solenoid is going bad?

Answer
Hi Bryan
It sounds like to me that your magneto is breaking down. Remove the magneto and check for rust and buildup on the arms and also on the magnet area of the flywheel. Also check your cooling fins on the engine to make sure they are clear. When replacing the magneto the gap should be .010-.014. Hope this helps.