Why does my 15.5 hp Kohler quit when it get hot?

I have a John Deere LT155 with a 15.5 hp Kohler engine. The engine will back fire and quit after it gets hot. When it cools it will run again until it gets hot. Any idea on what could be wrong?|||the ignition coil could be getting hot and breaking down the coil windings. when the engine quits "when it gets hot" pull the spark plug wire off the spark plug and check the spark to see if it is a good blue spark if it does not the coil could be going bad|||Try taking the covers off the sides of the engine compartment; it will run cooler. It worked on mine. And check to see if grass or debris is packed around the engine. It only takes a little to block the free passage of air around it.|||the first thing i would try is replacing the spark plug.