When I start my weed wacker, it rev's up but as soon as I give it gas, it dies. Could this be from old or bad gas?

Thanks for your help,

Air filter.

You can throw some of them in the wash, so keep 1 handy.

Could be the air filter, but more likely to be old fuel, or the results of old fuel. Clean the carb if the air filter doesn't fix it, then of course, it could be the carb simply needs adjusting.