Small Engines (Lawn Mowers, etc.): Lawnmower start, briggs stratton, head bolts

Question
Even when cold my Briggs & Stratton MODEL 195702-0136-01 seven hp lawnmower engine will not start if choked. What does this indicate? What corrections/adjustments need to be made?
Thank you

Answer
When was the last time the valves were checked?  Are the head bolts torqued to spec?  Are there any leaks in the intake gasket(s)?

Is the carburetor so old and wore it needs a major overhaul including a new butterfly shaft?  If the butterfly shaft is really wore you will get an air leak and the engine is not drawing in the fuel.

Eric