- Debris or water in gas.
- Improper setup of mower.
- Operator abuse or neglect.
- Service pickup and/or delivery.
- Normal maintenance (tune-ups, carburetor adjustments, oil change, air filters, etc.).
- Broken or bent crankshafts.
- Unit operated with low or no oil.
- Mower is over two years old.
- Mower is used for commercial, rental, and/or professional (non-homeowner) use.