Winter time I am careful to sump when above freezing. If not leave them alone or run the chance of ripping the O Ring with Ice. This advice and lesson brought directly from the ramp at KMLT.
J
I forgot if you grab the drain and rotate it while pushing in slightly it clears some dirt..... Good Luck
I know a fella who did that, filled the tanks on a Super Cub, launched out of Kotzebue, headed for Anchorage, in winter. Plane had sat a lot for a long time, and he hadn't sumped the tanks that winter, using the logic you explained. He started off on one tank and didn't switch to the other tank till the first tank was almost dry....duh.
And, guess what? The other tank actually had a good bit of water--actually ice, in it. Frozen solid. Gas on top of it of course, and the tank was in fact full, just not all gas.
Fortunately for him, he wasn't that far from a village and was able to get there before he ran out of gas in the other tank.
Lessons: Even in winter, sump the tanks. If you cut an O-ring, get it replaced. I carry a spare sump drain and wrench to replace. But, I've sumped tanks many, many times in winter without damaging an O-ring.
Second, always verify that fuel flows from BOTH tanks early in a cross country. You don't want to get half way in the middle of nowhere and find out one tank won't flow fuel.
MTV