Was on the phone with that last post - I should probably be a little more explicit....
Yes, fuel aging could be an issue, and use of fresh fuel is preferable, BUT when it's your only source of power, and especially when at sea when winds & tides can alter your consumption quite substantially It's always worth having a good few percent in hand.
I normally carry three portable tanks. The one that doesn't get used this time is the first to be connected to the engine next time.
I always drain my carbs, as I run premix. My old Suz used to inject the oil downstream of the carb, so it wasn't the end of the world if I didn't drain it
The reason I always drained that one was when I tipped the engine & put it on the trailer I would always find a puddle of fuel in the air box because carbs are built to work at roughly horizontal (float valve), so tipping it 45 degrees & shoogling it around emptied the bowl through the main jet quite nicely!
As you have a 4 I guess it might travel in the back of the car? - that in itself is a very good reason to empty the carbs!
And of course if you have a nice DI 2- stroke there are no carbs to empty!