How to Replace Fuel Lines in Boats

The fuel lines on your boat, whether copper, steel or flexible hose, carry flammable or explosive materials from the fuel tank to the engine.

All fuel lines terminate in a hose, held  by a hose clamp.All fuel lines terminate in a hose, held by a hose clamp.
Because of the flexing and vibration that fuel lines on a boat experience, federal law requires a segment of flexible hose between metal lines and the tank or engine. This means that, even if you're replacing a metal fuel line, it's as simple as replacing a flexible hose.

Set an open-top spill container beneath the junction between the engine or fuel tank and the fuel line you wish to remove. Shut off all fuel valves that supply fuel to the fuel line you plan to replace.

Insert the blade of the screwdriver into the slot of the screw that tightens the hose clamp securing the hose to the engine or fuel tank. Turn the screw counterclockwise to loosen the screw.

Allow any fuel in the fuel line to drain into the spill container. Remove the flexible hose from the motor by pulling the end of the line that you loosened away from the motor. Remove the hose clamp from the end of the fuel line after you have drained it and pulled it free.

Move the spill container to the other end of the fuel line. Loosen the hose clamp and pull the line away from the motor. Remove the remaining hose clamp from the end of the fuel line.

Slide the hose clamp onto the ends of the flexible hoses of the new fuel line. Push the new fuel line onto the hose fittings on the motor and tank. Tighten the hose clamp onto the hose fittings.

Things You Will Need

  • Open-top spill container
  • Screwdriver


  • Inspect your fuel lines regularly for leaks by wiping them with a dry rag, then sniffing for fuel. Check them visually every time you stop the motor, before you start the motor or before you take on fuel.

About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.