How to Replace a Boat Gas Tank

••• Benjamin Griffith, Flickr.com Creative Commons License

If you are a boat owner, you know that one aspect of boat maintenance to keep a careful eye on is the condition of your boat's gas tank. Using preventative maintenance can help increase the life of your fuel tank, and other maintenance or repairs may bring your old tank back to life. Unfortunately, it is a reality that tanks sometimes need to be replaced, particularly if they leak or have other physical damage. It can seem difficult to replace a boat gas tank. As long as you go slow, take your time and double-check every step of the process, you can expect to replace your gas tank without encountering any serious problems.

Inspect your old gas tank and fuel delivery system to make certain that the tank needs to be replaced. If changing your hoses or making other small repairs will restore your fuel system without replacing the tank, then make those changes instead. It is not particularly difficult to replace a boat gas tank, but any time you replace parts, you have the potential to cause other problems, so only change your tank if it is absolutely necessary.

Drain the fuel from your tank. Shut off all of your fuel lines and hoses, then either pump or siphon the gas out of the gas tank. Reconnect your hoses and turn the fuel lines on. Start the boat engine to burn off any fuel that may remain in the system. Removing fuel from the tank makes it much easier to work with. If you have a metal gas tank, it is also necessary to prevent a fire being started from a spark that may be generated when moving the aluminum tank out.

Disconnect any hoses that are attached to the gas tank. You can leave them connected to the engine for the time being, but they will need to be free from the gas tank before it can be removed from the boat. There is usually a fill hose, a vent hose and a fuel line. Disconnect all of these hoses. Also remove the Fuel Gauge Sending Unit from the inside of the gas tank.

Remove the gas tank. Start by taking out the safety brackets that secure your boat's gas tank in place. Be sure to save any screws or bolts that you remove, as these will be needed when you install the new gas tank. With the brackets out of the way, take the old gas tank out of the boat and dispose of it.

Place the new gas tank in the boat. Slide it into position where the old tank use to be. Once the tank is in position, replace the brackets. Use the old screws or bolts to secure the brackets in place so that they will prevent any sliding or movement of the new fuel tank.

Inspect your hoses. Check your hoses for any cracks or breaks. If your hoses look worn, replace them with new ones. Otherwise, reconnect all hoses to your new gas tank. Also replace the Fuel Gauge Sending Unit so that your gauges can tell you when you are low on gas.

Refill the gas tank. With a fuel tank, start your boat's engine and monitor all lines and hoses to make sure there are no leaks. If there are no leaks and everything looks good, your job is complete.


  • It is possible to switch to a larger or smaller gas tank than what was originally installed, but it is recommended to try to use an identical tank whenever possible. In many cases, you can purchase an OEM (original equipment manufacturer) gas tank that meets the exact specifications and dimensions of the original. Using an OEM gas tank will have the best results when you install the tank.

About the Author

Jerry Garner has been writing semi-professionally for more than 15 years. The body of Garner's work includes informative articles, news and current events and historical essays. He is an avid sports fan and frequently writes about outdoor activities online.

Photo Credits

  • Benjamin Griffith, Flickr.com Creative Commons License