Unlike cars, boats come with two types of engines and those are an outboard and an inboard engine. An outboard engine is the one used at the back in order to help power and steer the boat. Inboard engines, on the other hand, are meant to drive the boat which is why they are found behind the propeller.
When you turn, an inboard and an outboard engine won't pivot in the same way. Inboard engines are generally 4 stroke engines and act a lot like the one in your car. They power a drive shaft that runs through the bottom of the hull and it's connected to the propeller. The propeller also dictates your boat's acceleration speed as the faster it spins the faster the boat will move.
Symptoms of a Bad Fuel Filter
Idling
Rough idling may not indicate directly towards a faulty fuel filter but its misfiring could be because of it. You see, if the air-fuel mixture is not in check it could make the engine act up in all kinds of ways. One of the easiest solutions to this issue could be to get a new marine fuel filter in order to help make the air-fuel mixture stay adequate.
Startup
Again, an engine that won't start up could be caused by many different components and one of them could be the fuel filter. This is because contaminants can easily enter the engine if the fuel filter for a boat isn't working correctly or if it's clogged. Keep in mind that this can be accompanied by damaged fuel lines or an empty tank.
Brown Fuel
You may not notice the fuel filter going bad but when it does you will notice brown fuel flowing in the lines and to the engine. This could mean that the filter is due for a replacement or that something has clogged it. If you get brown fuel contaminants have gone through and made the filter brown too.
Vacuum Gauge
Another way you can troubleshoot your boat's fuel system and fuel filter is to check the vacuum gauge. If it shows a high reading it can be because there is too much pressure in the filter which is caused by too many contaminants.
Start & Stop
If the engine is stopping and starting on its own at any given time then you might want to check the fuel filter. This may not be directly tied to the filter but it can be due to poor fuel quality.
What Matters in a Fuel Filter
Details
The devil is in the details and it's no different with a marine fuel filter which requires a vacuum gauge when it comes to being able to tell how if the filter is contaminated and how much contamination it has. Remember that not all filters will meet UL marine fire resistance requirements which makes them more vulnerable to fires.
Numbers
There's safety in numbers and that is no different with boat fuel filters as the more you have on board the better the filtration and the fewer the number of issues you'll encounter. You can also go for larger boat fuel filters to make filtration far more efficient and less complicated when it comes to replacement.
How to Replace a Marine Fuel Filter
What You Need
There are certain tools and materials that you'll need before you get your hands dirty. These are paper towels, disposable gloves, oil absorbent pads, and some zip lock bags together with wrenches, a small funnel and screwdrivers.
Replacement
- To start replacing a boat fuel filter, you should first turn off the fuel petcock, if there is one, in order to prevent fuel from getting out of the tank. Then unscrew the T-handle found on the top of the filter and remove the cap on it.
- Once the T-handle and cap are removed, lift the old filter out of the casing and put it in a ziploc bag. After that, make sure to get rid of the O-ring found on the base of the threads of the T-handle as that needs to be replaced with every filter replacement. You can use a thin-blade screwdriver for this.
- Once all of the above is done you can put the new fuel filter for a boat in the filter element and put fresh oil in it. It would help if you also smeared some of the oil on the areas where new gaskets and O-rings will sit. This will help seal them properly.
- The cap should also be replaced with every filter replacement and make sure that when you do so you have the cap seated in the filter housing properly. Once you're done with the primary fuel filter, next comes the secondary filter or filters, depending on your vessel. Secondary filters are found closer to the engine, usually after the lift pump.
- When you're done replacing all the boat fuel filters, remember to place the oil-absorbent pads under them. This will help keep any leaking oil in one place instead of going all over the hull. It also requires installing O-rings for the top carrier and bottom bowl. Once done, just put everything back together and avoid overtightening the bolts and you're all done.
