Mercury - Fuel Line Assembly Portable Fuel System Rubber Composite 8M0061811. Overview. Every boater knows the quiet relief that comes when your engine fires on the first turn of the key. It's a small moment, but it sets the tone for the whole day-steady, calm, predictable. A good fuel line has everything to do with that feeling. The Mercury Marine part 8M0061811 Fuel Line Assembly brings that kind of confidence back into your setup, keeping fuel flowing cleanly and consistently whether you're d