Out of all these ideas IMHO, only one person gave you the right answer.
You alluded to the correct answer yourself when you mentioned that you never drained the gas from the prior year.
When gas is left in the carburetor (regardless of the brand of small or large engine) for a long time, it begins to evaporate, leaving "varnish" behind which plugs up all those little holes in the carburetor that need to be open for the correct air/fuel mixture to get to the engine for both starting and running. It is VERY likely that your carburetor is nicely plugged up. You may get it working with carb cleaner however it's more likely that you will need to remove the carb and clean it thoroughly.
Changing the spark plug after five years wouldn't hurt anything, but unless it appears worn it's probably not needed. These little engines are pretty tough, but do yourself a favor and change the oil frequently, change the plug every few years and ALWAYS drain the gas if you're not going to use it fr the next few months. If you don't want to drain the gas, you can use a product called "StaBil" that is designed to stabilize the fuel. It's also not a bad idea to spray an oil fog into the cylinder prior to putting it up for the winter. Of course, do that only if you really want the engine to last for a very long time.
-Jeff
MRS. CLEAN wrote: