I do the clear tube test on the workbench with a fuel source hung above the carbs. You need the bottle above, but not too far, or it will overpower the float needles.
Some clear tubing on the flow bowl nipples, and you are in business. If bubbles appear in the tubes, I flick the tube with a finger and work the bubble out. It's pretty easy. What's not so much fun is filling, measuring, draining, bending float tang, then repeating...which out splashing some gas on yourself. Wear your grubbies!
