The best method I've found: Fresh non-ethanol fuel with some Sta-bil, your choice of oil, and stored in a metal can.
You can find real gas locally by going here:
http://pure-gas.org/
If you really need it running now, take it to a real lawn supply place and have them service it for you. Next time you use it, use only real gas. Drain and run dry for storage over the winter.
Next spring put in new fresh fuel mix and have at it.