Went out to my property to mow with my 2015 L3901 and found the fuel filler cap missing. The tractor was sitting within sight of chip road so I don't know if I left loose, raccoon spun it off, or someone else lost theirs and mine was a handy replacement. I lean towards the last scenario, but it really doesn't matter, I got to deal with results now. I haven't used the tractor for several weeks and we've had quite a bit of rain. I'm sure I need to drain and remove the tank, rinse and refill. Change fuel filter and clean out water separator. Is there anything else I need to do to it?