Small Engines (Lawn Mowers, etc.): simplicity 22 hp briggs loosing power after warm up, simplicity riding mower, hp briggs

Question
I have a simplicity riding mower, 22 HP model 386777. It cranks good and mows good for about 15 min and then instantly loses power,skipping, running rough and can smell gas fumes, seems to be misfiring, let it cool and exact same happens again, replaced plugs. will coil fix it? and are there any diodes in spark plug cables?   thanks

Answer
I do not believe the engine had any diodes in the plug cables.  Only one series I know of has any diodes in the ignition harness and it is a V twin model.

What is the engine type number?  What brand of plugs are you using?  Do you have an inline spark tester you can use to see if the ignition coil is producing spark when the engine is warm?

Eric