Honda TRX680FA Owner's Manual page 191

Tires
Air Pressure
Refer to Saf ety Precautions on page 129 .
Properly inflated tires provide the best combination of handling, tread
life, and riding comfort. Generally, underinflated tires wear unevenly,
adversely affect handling, and are more likely to fail from being
overheated. Overinflated tires make your ATV ride harshly, are more
prone to damage from surface hazards, and wear unevenly.
Make sure the valve stem caps are secure. If necessary, install new caps.
Servicing Your Honda
183