I have a STX38 with a yellow deck. And the hood off. That's a whole other thing. It will fire right up and run like a champ when it's cold. But if I turn it off, even for a short as 30 seconds, it won't restart. The engine turns over fine and will crank and crank. But won't start. If I let it sit about 2 hours and cool down, it will start back up and run again until I turn it off.
Hands on, inspect everything electrical, wire harness, connections tight, no bare wires, ground wires tight, all plug in connections remove one by one visually inspecting terminals as well as all relays and safety switches and reconnecting after inspecting each one. Also take a good look at neutral start switch under brake pedal. Lastly I would adjust valves per B&S specs., replace spark plugs & air filter, change oil & filter.
