The fitting is a 1/4" vaccum fitting. These are generally white or black plastic type stuff... just a tube but they have RIBS on each end to join vacuum hoses and you can actually put some teflon tape on the end that you screw into the hole where the drain screw WAS and it stays pretty dry. Just find a piece of clear plastic tubing and put on the exposed end of the vacuum fitting. As far as having lines, not necessary if you know how far 4 or 5 millimeter is by eye but if you are unused to gauging millimeters by eye, then draw a couple marks on the clear tube with an indelible sharpie. The top line will be for holding next to the gasket mating surface and the bottom line will be where the gas is supposed to be in the bowl. When the bowl fills, air bubbles will trap where the fitting enters the bowl so you have to tap them out or gently blow into the tube to move the bubble out of the opening. Let the gas level settle and if it is too high or too low, bend the tang (piece that contacts float needle) up or down to adjust the height of the gas in the bowl (bend UP for less gas with carbs on the bike and bend DOWN for more gas with carbs on the bike).
