At first look,seems a carb problem.Did you check screws adjustment,about one turn each out.Next,you could clean it and maybe you gonna need a carb kit.Check also if the fuel line is still in good condition.
Set the setting H 1 full turn out, and L 1 full turn out, it will start on this.
If this does not help strart be the tank and move up as you elimenate stuff.
i found out why it dies, the spark plug boot is loose and it vibrates loose and makes it die. i squeezed it together slightly and it ran good for 15 minutes.