Small Engines (Lawn Mowers, etc.): burning out coils, briggs stratton, fuel tank cap

Question
I have a Briggs & Stratton, Model # 461707, Type 0143E1, Code 0011165A, bought 11/23/01.  While mowing the mower starts loosing power when turning, then backfires and after turning off engine it will not start.  Replaced coil and was running fine but after approx. 40 minutes use started doing the same thing.  Now it will not start.  Any ideas of what to look for.  Thank you.

Answer
Dean

Problem: Engine starts easily but dies after a few seconds.
Possible causes:

Fuel tank is empty or shutoff valve is closed, or fuel line or fuel tank cap vent is clogged.
Carburetor is overchoked.
Carburetor is improperly adjusted or needs service.

Problem: Engine idles roughly, unevenly, or surges.
Possible causes:

Carburetor is dirty.
Air leak in carburetor or intake manifold (e.g., bad O-ring, gasket, primer).
Carburetor is improperly adjusted or needs service.

Problem: Engine misses under load.
Possible causes:

Spark plug is fouled, improperly gapped, or damaged.
Breaker points are pitted or improperly gapped, breaker arm is sluggish, or condenser is bad.
Carburetor needs adjustment or service.
Fuel line, fuel filter, or fuel tank cap vent is clogged, or fuel shutoff valve partially closed.
Valves not adjusted properly or valve springs weak.