Tough call on this one. Ethanol laced gasoline begins a phase separation, after 90 days. The gas, ethanol and water separate into layers and "can" if left in the tank, long enough form a nasty looking orange jelly. You're probanly ok but I would disconnect the fuel line, as close to the tank, as possible and pipe it to your container. By piping, I mean, a hose. I would want to watch every drop, that came out, just in case, you get a little jelly, for your toast. A clear glass filter housing or clear gas rated hose, should work. A regular gas line emptied into a clear container should work, as well. You may be able to get a syphon going. I hate saying this but I wouldn't hesitate, you could put very slight pressure on your tank, to get flow. The tank will be vented but still takes very little pressure. Taking the gas from the line going to the engine will let you take a look at exactly what is going there. This may sound like a little overkill but your just emptying the tank from the bottom, instead of pumping or syphoning it out the filler neck. If you get some junk, then it's in a container and not running thru your carbs or injectors. Your going to treat your gas, next year, aren't you? I believe you