I've got two planes with the Dubro quick filler and a 2 line setup. It has worked fine. My subsequent planes have a 3 line setup. The engines are mounted inverted. I've had no problem with flooding. While fueling, I have the carb set at idle position. Even if I do get some fuel in the carb during filling, it's not going to flood the engine, unless liquids can flow uphill. However, these are all 2 strokes.