If you've decided it is time to change or clean the gas filter, there are a couple of basic types which are all easily serviced or replaced. Most motors utilize some form of an inline filter either between the gas tank and pump or between the pump and carburetor(s) or gas injection vapor separator tank.
Some inline filters are solid metal or clear plastic housings which are clamped in the middle of two gas supply hoses. This style is easily removed and replaced by undoing the clamps and carefully pulling the hoses free of the filter inlet and outlet nipples.
Other inline filters consist of a 2 piece plastic or metal housing where a gas filter bowl can be removed from a filter cap. The bowl often threads into position or is secured by a knurled knob which can be loosened by hand in order to remove the bowl. Inside the bowl or cap of this style filter you'll find a removable filter screen. If the screen is not damaged it can be rinsed in solvent and air dried (or VERY carefully blown dry using low-pressure compressed air). When in doubt, this type of filter screen is easily and inexpensively replaced.
Before checking the gas pump, make sure you've got clean gas filter/water separators. Finally, many boats and some motors are rigged using a disposable spin-on gas filter or fuel filter and water separator. These filters resemble automotive oil filters and are removed or installed in exactly the same fashion. Often you'll want a strap or cap wrench for removal, as they tend to get stuck in place after a season's use. Once unthreaded, you'll normally find a small rubber gasket which again looks just like the gasket on an oil filter. Before installing a replacement spin-on gas filter, be sure to lubricate the rubber gasket with a small dab of engine oil (again, just like with a spin-on oil filter) to ensure a good seal and to help make sure the filter comes off with ease next time you need to replace it.
iboats.com carries an extensive line of gas filters and water separators.
Marine Fuel Filters How-Tos
Efficiency in Water Separation for the Marine Industry
Why is the Racor water separation fuel system so much better than other systems?
In the marine industry, water is an enemy to boating engines, parts, hardware and all materials on the water. It is critical to use only the best water separation system for keeping particulates from your fuel, thus safe-guarding and prolonging the life of your engine.
Racor water separation filtration systems rank top to any other marine water separation system. Why would you risk using anything else? In the graph below you can see that a racor separation system maintains the highest removal efficiency, over a longer duration, than any other system on the market.
Why is Racor so much better that other products? It uses the highest quality Aquabloc media, which meets or exceeds efficiency requirements for OEM fuel injection systems. In its filtering systems it uses the highest quality automotive grade gaskets and seals. Its materials are temperature rated for a wide range of temperatures - from minus 40 degrees to plus 255 degrees Fahrenheit. They are also certified against the casting cracking due to extreme climatic and vibration conditions.
The Real Facts About Fuel Water Separating Filters (Video)
Video presentation on the difference between the Mallory water gas separators and other competitors. - Presented by Mallory Marine
Hi, I'm Jim Self from Mallory Marine. Mallory Marine continues to lead the filtration market with some of the highest quality marine filters in the business. Their leadership began when we came out with our first ten micron water separator. One of the first ones in the marine marketplace.
Due to the popularity, some of our competitors have come out with their own ten micron marine filters, and tried to discredit the quality of ours versus theirs with some misleading claims.
Their new 10 micron gas water separator filter is superior due to their larger filter element and more filter media. Their claim would be completely accurate if we are talking about oil filters, but we're not. Gas water separators are designed using different principles for different intended functions.
Filtration technology is vastly different when comparing gas water separators to oil filters. With a gas water separator you want to have enough filter media here to not impede the gas flow when maximizing your water hold capacity. Remember, the purpose of this is to separate water from the gas.
No filter media will completely block water. The key to the design is to prevent water from coming in constant contact with the filter media as long as possible. To prolong service life, and maximize your water hold capacity.
With our competitor's filter design the element sits much lower in the canister and is going to come into contact with the water much sooner. Which is going to allow water to pass through into the marine gas system.
With our marine filter design we have twice the water holding capacity and a much longer service life.
Don't be fooled by our competitors misleading claims.
Mallory features superior filtration and water holding capacity; Holds 2 times more water before coming in constant contact with the filter media; High efficiency 10 micron filter media; More than 90% efficiency at 10 micron particle removal; Superior resistance to water permeation; 90 plus gallons per hour gas flow; Meets ISO10088 and USCG Title 33 CFR183.590 fire test requirements; And is approved for use with all ethanol blended gas.
No matter what your marine filtration needs are, Mallory has a wide variety of options, from our drainable, visible, high capacity, stand water gas separators available with aluminum powder coated bracket and three sixteenths stainless steel.
For more information on Mallory products, please go to our website at www.mallorymarine.com.
Keeping Marine Fuel Clean (Video)
How to keep your gas clean, presented by Fishing World.
Outboard engines like this Honda Marine obviously need gas to run. When you mix petrol with water, some problems can occur. You need to understand how these things can be dealt with and how to prevent them.
The first thing I would like to talk about is ethanol blended gas. It stays still a few cents cheaper than most petrol. While these marine engines can run on ethanol blended gas with no problems at all, it is probably not a great idea to fill your boat up with ethanol gas because: A, they are hydroscopic. That means they actually attract water; and B, they can cause some problems with some types of marine gas tanks and also some types of rubbers in your gas lines and so on. I probably recommend you stick with your normal unleaded or premium petrol for your outboard marine engine.
The other thing to think about with gas is that water in gas can cause really big problems with your marine engine. And it is a fact of life that when you are on the water in a boat, you are going to sometimes get some sort of water in your gas. The way to deal with that is by installing the proper type of marine gas filter.
This one here is a great example. It has a glass bowl down here so you can see that any water that comes through the filter is deposited into this glass bowl. And then you could drain it off.
It is a really good idea to mount your marine gas filter in a great spot like this where it is easy accessed. The Boat guys have done a fantastic job mounting this gas filter somewhere you can readily see what is going on. And you should check it every time you go out. If there is any water at the bottom, you can easily see the water. It looks like a sort of a little greasy pool there at the bottom. Sometimes it is mucking it. You simply dry it out in a container and then dispose of it in the proper way.
Engines like this have also got a couple of other fuel filters in them. They are called inline fuel filters and they are basically the last line of protection for your engine. These filters are located in here. If any water gets from here that goes into your engine, these gas filters will hopefully get it.
These they change in an annual basis when you take your engine in for a service. It is really important to make sure that your fuel filters are changed on an annual basis. You check them regularly, you drain off any excess water, you get these guys service once a year and replaced.
Other ways you can minimize the risk of water in your gas is by making sure that your marine gas tank is full before you stow your boat. What happens, when your gas tank is half full or three-quarters full and you put your boat away for a week or two before your next fishing trip, is that sometimes moisture-laden air can be drawn in through the breathers. And what happens then is that the moisture in that air turns into water droplets that goes into your gas and can cause big problems.
If you fill your tank up so that it is right full. That means is that there is only a very small amount of air or possibly no air at all can get in and deposit any water. That is a really good practice every time you have a day out. Put the boat back on the trailer, get past the surveyor, fill her up, and you can store it. And you know you are going to minimize that risk of water in your gas.