Small Engines (Lawn Mowers, etc.): B&S 16hp cast iron carb flooding & missing under load, compression check, shutoff valve

Question
I have a 16hp CI (simpicity 7016H) engine with following symptons:

gas drips out of carb after sitting. I have to close shutoff valve after mowing.
mis fires under load
will not start and floods after a hot shutdown

I have cleaned (you could eat off of it !) rebuilt the carb carefully 3 times and properly adjusted carb according to the manual. This is a large two piece flo Jet carb. I even bench checked it with water to see if it leaked from the float area and didn't. The needle and seat worked properly but it was COLD. I Replaced magneto (.012"),spark plug (J19LM, .030"),plug wire, wiring, points (.020").

I have a new B&S carb on order. If this does not solve the prob. what could it be ? Could it be valve related. If so, what test would you recommend to diagnose ? A compression check ?

Thanks for your help...Flint  

Answer
Hi Flint,

The only cause of a leaking carb and flooding, that I know of, is float related.  A new carb should solve the problem.  If you still have misfiring problems at that point, I would do a compression test to check the valves.

Let me know how you make out.
Michael