I have been using this eqiuipment for 2 years.....I always had a difficulty starting this blower (in comparison to all my other gas powered machines) Now it will not start at all. I replaced the spark plug, to no avail. It seems there is no spark whatsoever. (and yes i had the switch in the on position) what can i do to troubleshoot this< Is there a batterry that provides power to the spark plug? Magnito?