Yes, the large phillips-head screw in the center of the tank can be removed
to drain or to check for possible water in tank. Be sure to use a large tip
phillips screwdriver to avoid stripping the head. I recently drained the
tank in my 240DL in order to check the condition inside(having also removed
the send unit/fuel pump assembly). If the flow of gas slows to a mere
trickle you might have some rust/debris blocking the hole. Mine did that, so
I stuck a small phillips screwdiver into it periodically until all fuel was
drained. Consider the amount of fuel in tank and use a good sized container
or pan to drain into. Good luck.
