Many complaints of "hard to start", or "runs rough" are due to old gas.
Today's gas is Ethanol, which contains alcohol made from corn. This was mandated by our govenrment. A result of this stuff is that it gets old/stale quickly. It reacts with the humidity in the air (power equipment have vented gas caps, allowing air to enter)and can happen in 30 days!
Ways to extend this shelf life is to:
1. Add fuel stabilizer to gas cans.
2. Keep gas tanks full (limits amount of air that can enter a tank.
3. Store gas in sealed containers, and in dry locations out of the sun.