Fuel tank is empty.
Fuel system leaks.
Starter relay connections loose or corroded.
Low battery voltage.
Wrong engine oil.
Wrong fuel. (See “Using Proper Fuel” in “Service Miscellaneous” section).
Water, dirt, or air in fuel system:
Check fuel filter. Drain, flush, fill, bleed system.
Dirty or faulty injectors.
Fuel shut-off solenoid failure.
Operator off the seat and parking brake is not locked.
Loose or corroded electrical connections.
Forward and reverse pedal must be in the neutral position.
Mow-transport lever must be in the transport position.