How To Safely Remove Bad Fuel
From Boat Fuel Tank

Paul Luisi
by Paul
Luisi

Removing bad  fuel from the marine fuel tank helps stop fuel contamination.

Water, algae and debris like sludge or varnish can get into the fuel tank causing the fuel to go bad and this can create problems for the boat.

The instructions below apply to both diesel and gasoline boat engines.

To safely remove bad fuel from a boat fuel tank:

  1. Use A Suction Pump To Drain Bad Fuel From Boat Fuel Tank
  2. Spray A Fuel Tank Cleaner Into The Boat Fuel Tank And Rinse With Water
  3. Use A Suction Pump Again To Pump Out The Dirty Water Into A Bucket Or Container
  4. Fill Boat Fuel Tank With New Clean Fuel
  5. Contact Local Marina Or Disposal Center For Safe Dumping Instructions
  6. Dump The Fuel In Accordance With The Hazardous Waste Fuel Disposal Instructions Provided

These steps will ensure the bad fuel is removed from the boat fuel tank and disposed of in a safe and secure way.

Step 1: Use A Suction Pump To Drain Bad Fuel From Boat Fuel Tank

When draining a boat fuel tank:

  • Use a suction pump: This will pump the dirty and bad fuel out of the marine fuel tank.
  • Make sure fuel tank is completely empty: Ensure every drop of the dirty or bad fuel has been removed into a bucket or container.
  • Use a bucket or container that can be sealed: A sealed container will help prevent spillage or environmental harm.

Depending on the size of the fuel tank, this step should take approximately 10 - 20 minutes at most.

Summary
The suction pump will remove all the bad fuel from the boat fuel tank. Get a container or bucket to collect all the bad fuel safely.

Step 2: Spray Cleaner Product Into Boat Fuel Tank And Rinse With Water

Use a boat fuel tank cleaner and spray it into the empty fuel tank. This will: 

  • Remove dirt left from bad fuel:  The cleaner will help dissolve any residual dirt left from bad fuel in the fuel tank.
  • Dissolve any trapped sludge or varnish: A fuel tank cleaner will help dissolve any trapped sludge and varnish.
  • Prevent future fuel contamination: The cleaner will help prevent any new fuel from being contaminated as the dirt will be removed.

Use a marine grade fuel tank cleaning product when removing dirt from fuel tank.

Do not use any product that is not marine grade.

The top fuel tank cleaner products list will help with choosing the right cleaning spray to use.

After spraying the fuel tank with cleaner, rinse it with water.

This will loosen up the remaining dirt and the soapy cleaner used to clean the tank.

Summary
Spraying the fuel tank with a cleaner will help remove any dirt build up with the bad fuel. This will prevent future fuel contamination.

Step 3: Drain Dirty Water From Boat Fuel Tank Into A Container

Use the suction pump again to pump the dirty water and cleaning product out of the boat fuel tank and into a bucket or container. This will:

  • Ensure new boat fuel won't be contaminated: A clean fuel tank means the new boat fuel won't go bad or get dirty.
  • Help with engine performance: With no dirty or bad fuel in the tank, the engine will run better.

This step should take no longer than 5 - 10 minutes to complete.

Summary
Drain the cleaner product and dirty water into a sealed bucket or container. Having the fuel tank clean will help prevent new fuel from going bad.

Step 4: Fill Boat Fuel Tank With New Clean Fuel

Make sure the bad fuel, dirt, soap from the cleaner and other residue has been fully removed from the boat fuel tank.

Then fill the tank with new clean fuel. If you've removed the bad fuel correctly, the boat engine should be fine.

Step 5: Contact Disposal Center Or Marina For Safe Dumping Instructions

After fully removing the bad fuel from the marine fuel tank, it must be safely disposed of.

To safely dispose of the bad fuel:

  • Contact a local marina or disposal center: Usually a local marina will have all the information required to safely dispose of the bad fuel from the boat.
  • Ensure the bad fuel is in a certified sealed container: Ensure the bad fuel and dirty water is in the correct and certified container so no leaks occur.

Some disposal centers might not take the bad fuel waste if it's not in a proper certified and sealed fuel container.

Contact them before transporting the waste to ensure the local safety requirements are met.

Summary
Contact a local disposal center or marina for safe disposal instructions of the bad fuel.  Typically, a local marina will have details on how to find a safe dumping place locally.

Step 6: Dispose Of Bad Fuel In Accordance With Safety Instructions

Transport the bad fuel in a sealed container to a nearby disposal center or dumping location.

Then simply dispose of it in accordance with the disposal centers instructions.

Typically, there will be a fee for dumping the bad fuel. In most instances, it won't cost more than $20 to dispose of it.

Summary
Transport the bad fuel to the disposal center and dispose of the fuel in accordance with safety instructions. In most instances, it won't cost more than $20 to do this.

Products Needed To Remove Bad Fuel From Boat Fuel Tank

To remove bad fuel from the boat fuel tank, the products needed are:

  • A certified sealable fuel container or bucket: This is to ensure safe transport of the bad fuel to a disposal center
  • A fuel suction pump: This will help pump out the bad fuel from the boat fuel tank.
  • A boat fuel tank cleaner: This will help remove dirt and prevent any new fuels from going bad.
  • A pair of gloves: This is to protect skin from any chemical irritants.

With these products, you will be able to safely dispose of bad and dirty fuel.

Summary
Get a fuel suction pump, a pair of gloves, a certified sealable container and some boat fuel tank cleaner to safely remove bad fuel from boat fuel tank.

Professional Fuel Removal Service

Another option for removing bad fuel from a boat fuel tank is to hire a boat fuel removal service.

Hiring a professional boat fuel removal service will:

  • Ensure the bad boat fuel is removed safely: A professional service will remove bad fuel safely as they will have experience.
  • Prevent engine or fuel tank damage: A professional company will know the do's and don't s of removing boat fuel from specific boat types. This will help prevent engine or fuel tank damage.

Typically, a professional fuel removal service will cost around $150.

Simply contact your local marina for contact details for these services.

Summary
An alternative option is to hire a professional fuel removal service to do the work. Contact your local marina for information on where to find these services.

Boat Fuel Removal Summary

These bad fuel removal instructions apply to all types of boats and boat fuel tanks.

There are many advantages of cleaning a boat fuel tank and removing bad fuel including improved engine performance and more importantly preventing engine damage.

Removing the bad fuel from the vessel's fuel tank should take no longer than 25 minutes from start to finish once you have the right products.