Fuel Tanks - Portable, Top Side & Below Deck

Portable Fuel Tanks, Top Side Fuel Tanks, and Below Deck Fuel Tanks - Resources & Information

Fuel tanks are essential components for boats and outboard engines to provide a safe way to store and transport fuel to propel you across the water. Over time, contaminants in fuel and environmental factors can damage your fuel tanks and related components, leading to poor performance, leaks, and internal engine damage. 

PartsVu offers a complete selection of Portable Fuel Tanks, Top Side Fuel Tanks, and Below Deck Fuel Tanks from OEM manufacturers and trusted aftermarket suppliers, including:

• Portable Fuel Tanks
• Top Side Fuel Tanks
• Below Deck Fuel Tanks

Whether you need portable jerry jug, a fuel cap, a matching fuel pick up assembly, and more, PartsVu has what you need to get the job done. 

Need help servicing your boat and outboard engine? PartsVu regularly publishes helpful how-to guides and other valuable maintenance information to help boaters service their outboard engines, boats, trailers, and more. Browse the PartsVu Xchange, our outboard maintenance blog, for a wide range of relevant topics and review the FAQ section below, covering everything you need to know about maintaining your boat in confidence.

Fuel Tanks - Portable, Top Side & Below Deck FAQ

What are the most common types of Fuel Tanks on boats?

There are several different types of fuel tanks that are commonly used on boats:

• Portable fuel tanks are small, lightweight tanks that can be easily carried by hand. These tanks are often used on small boats or as a backup fuel source for larger boats.
• Top side fuel tanks are mounted on the deck of the boat, typically near the transom. These tanks are convenient for refueling and are easy to access, but they can take up valuable deck space and may be prone to damage if the boat is hit by waves or rough seas.
• Below deck fuel tanks are mounted inside the hull of the boat, typically in a dedicated compartment. These tanks are generally more secure and protected from damage, but they can be difficult to access for refueling and maintenance.

Regardless of the type of fuel tank being used, it is important to choose a tank that is appropriate for the size and type of boat, and to follow proper safety procedures when handling and storing fuel.

What are marine gas tanks made of?

Marine gas tanks are typically made of a material that is resistant to corrosion and can withstand the rigors of being used on a boat. The most common materials used to make marine gas tanks are aluminum, stainless steel, and polyethylene plastic.

• Aluminum gas tanks are lightweight, durable, and resistant to corrosion, making them a popular choice for use on boats. They are typically welded together using a process called TIG welding, which creates a strong and permanent bond.
• Stainless steel gas tanks are also durable and resistant to corrosion, but they are heavier than aluminum tanks. They are typically welded together using a process called MIG welding, which also creates a strong and permanent bond.
• Polyethylene plastic gas tanks are a relatively new option for marine use. Also referred to as poly marine fuel tanks, marine poly fuel tanks, and plastic boat tanks, this variety of fuel tank is lightweight, corrosion-resistant, and can be molded into a variety of shapes, making them a good choice for custom applications. They are typically joined using a process called rotational molding, which involves heating and rotating the plastic to create a seamless and leak-proof tank.

Regardless of the material used, marine gas tanks are designed to be strong and durable to withstand the rough conditions of being used on a boat. They are also designed to be safe, with features such as pressure-relief valves, venting systems, and fuel gauges to help prevent accidents and spills.

How to drain boat fuel tank?

To drain a boat fuel tank, you will need to follow these steps:

1. Locate the fuel tank. It is typically located in the engine compartment or under the floor of the boat.
2. Locate the fuel tank valve. This is a valve that controls the flow of fuel from the tank.
3. Turn off the fuel valve. This will stop the flow of fuel from the tank.
4. Locate the fuel drain hose. This is a hose that is connected to the bottom of the fuel tank and is used to drain the fuel from the tank.
5. Place a container underneath the fuel drain hose to catch the fuel as it drains out of the tank.
6. Open the fuel drain valve. This will allow the fuel to flow out of the tank and into the container.
7. When the fuel has finished draining, close the fuel drain valve and remove the container from underneath the fuel drain hose.

It is important to follow all safety precautions when draining a fuel tank. Make sure to wear protective gloves and eye protection, and do not smoke or allow open flames near the fuel tank.

Is winterizing my outboard important?

While it’s always a bit more fun to pull out your boat than to put it away, properly winterizing your outboard engine should be mandatory for all experienced boaters. Winterizing helps avoid engine damage and will facilitate a smoother start to the beginning of next season - after all, no one wants to wait to get back on the water!

There are several important steps you should take when storing your MerCruiser outboard lower unit to ensure that it’s properly winterized.

1. Flush Your Engine - Thoroughly flush your MerCruiser engine to remove any salt buildup if you are a saltwater boater, or accumulated mud and grime if you are a freshwater boater. Failure to remove this debris from your MerCruiser lower unit leads to corrosion in the engine. And if you’re a saltwater boater, leftover salt crystals in the lower unit can act like sandpaper to your internal engine components.
2. Stabilize Your Fuel System - Fuel starts to go bad within 30 days of sitting in your fuel system. It is vital to use a fuel stabilizer when your boat will be sitting unused for more than two or three months. Adding the amount of fuel stabilizer directed on the product’s packaging to your fuel—for instance, 1 ounce of Mercury Quickstor Fuel Stabilizer for every 5 gallons of marine fuel ensures proper winterization for more than 3 months. 
3. Fog Your Engine - Fogging oil is a wax-based oil that coats the engine to prevent corrosion.
4. Change Out the Lower Unit Oil - It’s recommended by marine mechanics to change your gear lube before storage to make sure that there is no water in the lower unit’s oil. Any water in the oil could freeze, expand, and crack your lower unit. Additionally, old oil is more likely to gum up oil passages and corrode components due to changes in its chemical composition through regular use. Last, consult your owners manual for which oil is appropriate for your engine.
5. Disconnect Your Battery - Disconnect your battery and spray CRC Marine Battery Terminal Cleaner on your battery terminals.

What are portable fuel tanks used for on boats?

Portable fuel tanks are used for a variety of purposes on boats, including:

• As a backup fuel source: Many boaters carry a portable fuel tank as a backup in case the main fuel tank runs out. This can be especially useful on longer trips or in areas where fuel may not be readily available.
• For refueling: Portable fuel tanks can be used to refuel a boat's main fuel tank when it is running low. This can be more convenient than trying to refuel from a larger fuel source, especially if the boat is moored in a remote location.
• For transporting fuel: Portable fuel tanks can be used to transport fuel from one location to another, either by boat or by land. This can be useful for boaters who need to fuel up in areas where fuel is not readily available, or for those who need to transport fuel to a boat that is moored in a remote location.
• For storing fuel: In some cases, portable fuel tanks may be used to store fuel when the main fuel tank is not being used. This can be helpful for boaters who need to store fuel for later use or who want to keep the main fuel tank clean and free of contaminants.

Overall, portable fuel tanks are a useful accessory for many boaters, as they can provide a convenient way to store and transport fuel for use on the water.

What are the most common sizes of fuel tanks for boats?

The size of a boat's fuel tank can vary widely depending on the type of boat and its intended use. In general, however, fuel tanks for boats tend to range in size from as small as 25 gallons to as large as several hundred gallons (large vessels). Some of the most common sizes of fuel tanks for boats include:

• 25-50 gallons: Fuel tanks in this size range are typically found on small boats such as inflatable dinghies, canoes, and kayaks. These tanks are usually sufficient for short trips or for use as a backup in case the main fuel tank runs out.
• 50-100 gallons: Fuel tanks in this size range are often found on small to medium-sized boats such as runabouts, center consoles, and fishing boats. These tanks are generally sufficient for extended day trips or for use on shorter overnight trips.
• 100-200 gallons: Fuel tanks in this size range are commonly found on larger boats such as cruisers, express boats, and sport fishers. These tanks are typically sufficient for extended overnight trips or for use on longer voyages.
• 200+ gallons: Fuel tanks of 200 gallons or more are often found on larger boats such as trawlers, motor yachts, and other types of long-range vessels. These tanks are usually sufficient for extended voyages or for use as a primary fuel source on boats that are used for commercial purposes.

Smaller, more portable gas tanks are also found on many boats due to their utility and convenience. PartsVu sells a selection of fuel tanks of this type (with links to our most popular brands), including:

• 3 gallon marine fuel tank
• 5 gallon boat fuel tank
• 9 gallon marine fuel tank
• 12 gallon marine fuel tank
• 14 gallon marine fuel tank
• And more

What is a pontoon under deck fuel tank?

A pontoon under deck fuel tank is a fuel tank that is mounted underneath the deck of a pontoon boat, typically between the pontoons. These tanks are typically made of plastic or metal and are designed to be lightweight and easy to install. They are usually located in the center of the boat, near the engine, and are typically accessed through a hatch or other opening in the deck.

One of the main advantages of using an under deck fuel tank on a pontoon boat is that it helps to save space on the deck, which can be useful for boats that are used for recreational purposes. Under deck fuel tanks are also generally easier to install and maintain than other types of fuel tanks, and they can help to keep the fuel system clean and free of contaminants.