If you have any small engines in your garage (mower, rototiller, snow blower, chain saw, trimmer, pressure washer, etc.), whether they're two or four cycle, you will save yourself much aggravation and not a little cash by never pumping any gas into a gas can without adding STA-BIL or some other fuel stabilizer. Let me say it again: never pump any gas into a gas can without adding a fuel stabilizer! (I use Marine Formula STA-BIL.)
Today's gas is about 10% ethanol and ethanol is death to small engines, particularly their carburetors. If you can't start your small engine; if you're tired of pulling the cord seventy-five times before you hear anything encouraging; go ahead and rebuild your carb (or have your small engine pro do it for you). Then, after you pay him $50 or so, stop on the way home and fill your gas can with fresh gas, first pouring an additive into the can. If you always use a fuel stabilizer, you don't need to worry about overwintering your engines with fuel in their tanks. They'll start right up next spring.
Here's an article on a new additive Briggs-Stratton has developed to deal with this problem. The article is OK, but the comments are excellent.