Small Engines (Lawn Mowers, etc.): B&S 8 HP No Spark, halfway point, engine model

Question
I recently acquired a Craftsman 8 HP Shredder w/8 HP B&S Engine, Model 190432, Type 6117-01, Code 92093010. I have cleaned and rebuilt the carb with a complete rebuild kit. I got the shredder running and shredded a few branches. I shut the machine off and then went back to it a couple hours later but couldn't get it to start it again. I checked for spark by pulling the spark plug and watching for an arc. Would this work? The spark plug is new with the gap set at .030". When I pulled it out to check for spark, it was sooty black. Could it be fouled already after 20 or so minutes of starting and run time on it? Are there exploded views available so I know what to take off to check armature gap and what it should be set at?

Answer
The coil gap can be set with a folded dollar bill.  You'll need to remove the flywheel shroud to access it.  You can't adjust the coil out far enough to keep it from firing though.

If the plug is black, it's running rich.  Adjust the main mixture screw to 1 1/2 turns out then with the engine running at operating speed, turn it in until the engine runs rough and then back out until it runs smooth and then rough again.  The halfway point between where it runs rough is the setting.  Do the same for the idle screw but at slow idle.

If that doesn't help, then recheck the float and see that it's sitting level.