Marine Fuel Polishing

Fuel polishing services for diesel and gasoline marine engines– from mega yachts to jet skis and all boats in between.

The Problem

Is Your Fuel Tank Contaminated?

Your fuel tank keeps you going, but days on the water come to a halt when your boat won’t run. Contamination can come from many sources, like bad fuel or water. If left unchecked, your fuel tank can grow microbes creating biomass sludge in your tank.

Phase separation in fuel occurs when water has entered the tank. This can happen through condensation or badly mixed gas. This water then binds with the ethanol in fuel (even “ethanol-free fuel” contains small amounts of ethanol), dragging it to the bottom, leaving gasoline in the top layer. Fuel tanks pull from the bottom, so this watery ethanol mix will enter the motor first, causing an array of issues. All gas-powered boats, jet skis, and other marine engines are susceptible to phase separation due to the chemical makeup of modern gasoline and marine environmental conditions.


When to Clean a Boat Fuel Tank

Any time a boat or jet ski comes out of long-term storage, typically more than one off-season, the fuel should be polished before running it through the engine. Ultimately it comes down to use. If you don’t go through much fuel regularly, you may need to polish your fuel more often than other boat owners.

How do I know if I need fuel tank cleaning?

You may need to have your fuel tank cleaned and your fuel polished if you experience hard starting, power loss, uneven idle, exhaust smoke, reduced RPMs, or dirty fuel filters. If your boat suffers from any of the issues mentioned, contact us to get scheduled for fuel polishing & tank cleaning.

Cleaning Boat Fuel | Mojo Fuel

The Solution

How Does Fuel Polishing Work?

Fuel polishing works by removing water and contaminants from fuel. Fuel polishing restores octane/cetane levels and cleans deposits in tank & fuel systems. Polished fuel can be put back into a clean tank salvaging previously unusable fuel. Depending on contamination levels, we are usually able to save up to 90% of contaminated fuel. Polishing fuel & tank cleaning is an inexpensive maintenance procedure versus expensive repairs to major mechanical components.

Our Process

Our proprietary fuel polishing service goes above and beyond to save your fuel system!

Water & Sludge Removal

Water & Sludge Removal

Our team of professionals begins the cleaning process by gaining access to the bottom of your storage tank, carefully and thoroughly extracting the accumulated water and sludge. This step is crucial in preventing damage to your fuel system and ensuring the optimal performance of your equipment.



Once the water and sludge have been removed, our technicians proceed to filter the remaining fuel multiple times through our cutting-edge multistage separators. Utilizing a combination of high-performance centrifugal separators and ultrafine filtering technology, we can effectively remove any residual particulates and entrained water still present in the fuel.

Fuel Additives

Fuel Additives

During the polishing process, we inject chemical additives* to absorb water at the molecular level, restore cetane/octane levels, and add a cleaner that will treat internal fuel system components as the restored fuels are burned. *Our additives are petroleum-based, contain no alcohols or acids, and will not degrade hoses & gaskets or damage sensitive fuel system components.

Mojo Fuel | Marine Fuel Polishing

Frequently asked questions

I have a “Racor” water-separating filter, won’t that protect my engine?
It will… until it won’t. Your Racor and other filters are designed to protect your engine from minor fuel contaminations. If you’ve ever experienced a plugged filter starving your engine of fuel you understand that once that filter is full, it stops the flow of fuel. Where water is concerned, once the separator is overwhelmed, you often only find out that you have a problem when the water reaches the engine risking blown injectors and other major mechanical failures. Regular system maintenance is critical, and fuel polishing and tank cleaning should be a part of every boater’s regular maintenance schedule.
Isn’t it cheaper and better to just pump the contaminated fuel out and “start over” with fresh fuel?
In theory, this would work. But when you consider that pickup tubes don't reach the bottom of the tank intentionally, it is almost impossible to get ALL the fluids out of your tank. Additionally, you will not be cleaning the sides of the tank, and when you add new fuel, it will be contaminated by the mess left behind. In reality, you will end up throwing away a tank of fuel that could be restored and contaminating a new tank of fuel as well. Fuel is expensive these days! Give us a call to see how we could SAVE you money over throwing away your fuel.
How Do I Know if I Need Fuel Tank Cleaning?
You may need to have your fuel tank cleaned and your fuel polished if you experience hard starting, power loss, uneven idle, exhaust smoke, reduced RPMs, or dirty fuel filters. If your boat suffers from any of the issues mentioned, contact us to get scheduled for fuel polishing & tank cleaning.
What is the best way to maintain tanks in small boats and equipment?
Do not expose them to direct sunlight or extreme weather if possible. Keep them 90% full and use a full spectrum fuel additive. This regimen will eliminate 70-80% of potential fuel problems in any fuel tank.
How does water get into my fuel tank?
Condensation is the most common source of water contamination in fuel tanks. Additionally, many boaters fail to realize that the o-ring that seals the fuel cap to the deck fitting should be replaced annually.
My boat runs on gasoline. Can you polish gasoline fuel?
Mojo Fuel Optimization can polish and restore both diesel and gasoline!

Maintenance Program

Service Contracts for Marinas

Mojo Fuel Optimization offers a fuel polishing contract for boat storage facilities because reliable and professional marina managers know that proper fuel storage procedures are critical to boat maintenance. For a set per-boat fee, you can offer your seasonal storage customers the added benefit of an annual fuel polishing and tank cleaning service. This service is available for both gas and diesel boats. In the spring, we will set a time to service all of your stored boats before the boating season kicks off. Knowing that fuel problems will not interrupt the busy start of boating season for your customers will provide peace of mind and happy customers, setting your facility apart from all others. Contact us today for pricing and to schedule a consultation. Mojo Fuel Optimization is also available for contaminated fuel disposal. Mojo Fuel Optimization service contract features: A value add product to set your marine storage facilities apart. Recognized as an essential part of long-term boat maintenance. Will reduce launching interruptions during the busy season. Easy upsell can be added for a fraction of the single boat service price.

Mojo Fuel | Marine Fuel Polishing

Smooth sailing and uninterrupted adventures await, thanks to the rejuvenation touch of polishing for your boat!

Contact us today to schedule a fuel polishing service.