Mercury - Fuel Line Assembly with Primer Bulb Fuel System 8M0053987. Overview. A good fuel line doesn't draw much attention-until it starts acting up. This assembly gives you a clean, steady fuel supply for Force and Mercury outboards that use clip-on style tank and engine disconnects. The hose is flexible but tough enough to handle long days in the sun, and the primer bulb feels solid in the hand the way a proper marine line should. For anyone who's chased down sputtering issues on the water, h