Engine runs erratic Possible Causes and Corrective Actions

Spark plug boot loose
Connect and tighten spark plug boot.
Blocked fuel line or stale fuel
Clean fuel line and fill tank with clean, fresh gasoline.
Vent in gas cap is plugged
Clear vent.
Water or dirt in fuel system
Drain fuel tank and refill with fresh fuel.
Dirty air cleaner
Replace air filter.
Unit running with CHOKE (if equipped) activated
Push CHOKE knob in.