Small gas engines are always fouling the plug and getting gummed up in the carburetor. Even the gas gets messed up if it is stored too long.
I've got a 60 volt setup for all my stuff. It works with more power than I really need for the size of the yard.
Oh yeah 60v is sweet. I was cheap and wanted to be able to use the same batteries as in my drill etc :) Ever so 18v weed eater gets it done for all I need it to do.