I turn the key, there is a loud clunk, and the starter does not turn. The battery is good. I bypassed the starter solenoid and the same thing happens. I've checked the spark plug and it's getting fuel. The machine (a 17.5 hp unit) has less than thirty hours on it. When I removed the spark plug and briefly turned the ignition on, the engine turned over and spewed out some not so good looking gasoline.