4 Common Symptoms Of Clogged VST Filter 

symptoms of clogged vst filter
symptoms of clogged vst filter

The frequency of filter change depends entirely on the quality of fuel you’re using. Ideally, replacing the fuel filters after 50 hours of operation should be enough to manage the performance of your outboard.

However, if you’re using a higher-grade fuel, then this time can be extended up to 55 hours.

So, make sure to check the condition of the fuel filter on a monthly basis to avoid any extra issues with engine performance. With that said, many users have asked questions about the symptoms of clogged VST filters.

These issues can be quite frustrating as the engine starts to lack power.

So, if you also believe that you’re not getting the desired performance from the unit, then the following list of symptoms will give you a better perspective on the issue.

Make sure that you take your time and go through the steps mentioned below carefully.

This should help you in understanding why the problems appear and how you can prevent them in the future. People should also be able to learn how they can fix the issue even if it starts to appear on their engine.

Symptoms Of Clogged VST Filter

  1. Engine Sputtering

Even though the VST filter can last almost five times as long as the standard fuel filter, it can still get clogged when you don’t replace it for a few months.

Many users with a clogged VST filter point out that their engine will start sputtering.

While the sound is bearable, the major issue is that they would be unable to get any performance from the system. Similarly, the engine will die out immediately when you put any extra load on the outboard.

So, if you’re running into a similar problem, then your VST filter is likely clogged.

To get ahead of this problem, you need to replace the VST filter and install a fresh and clean filter in your unit.

While some anglers do believe that cleaning out the filter and installing it again will fix the problem, that is not the case.

You will run into the same issue within a few days, and the only solution is to get a new VST filter for your outboard.

Aside from that, you can also try to use better fuel in the system with some fuel stabilizers to extend the lifespan of your VST filters.

Otherwise, the filters will get clogged much quicker, and you won’t be able to fix your engine. Keep in mind that the problem should be dealt with as soon as you start getting these symptoms.


The main reason behind this is that continuing to use your vehicle like this can damage its engine.

If this dies out, then your only option is to get it replaced. Talking about this, the engine is the most expensive part of the vehicle which is why it is recommended that you take precautions beforehand.

As long as this is done, the boat should work perfectly without any further issues.

  1. Engine Not Starting

When the fuel supply is restricted from this filter, you will notice issues while starting the outboard engine.

Even though a few factors like a drained battery and effective wiring can play a role in this situation, clogged VST filters are one of the main reasons why you are running into this issue.

So, you can start by inspecting the spark plugs, wiring, and voltage output from the battery before changing the VST filters.

If you’re sure that there is nothing wrong with the spark plugs or the wiring cluster, then the only thing you can do is install a new VST filter in the setup.


Otherwise, you’ll be struggling to manage the performance of your outboard.

You can find these filters attached to the fuel pump, and they can be changed in under 10 minutes. So, reach out to your local dealer and purchase a compatible VST filter for your outboard.

You won’t need help from an expert to install this filter, and simply following the instructions in the owner’s manual should be enough to get ahead of this problem.

Keep in mind that people who are still feeling hesitant should still contact a specialist as it is much better.

Aside from this, the VST fuel filter that you purchase also plays a huge role in how it will work. This is why make sure that you purchase one that is supported by your engine.

Additionally, this should be from a reliable brand so that it can last you a much longer time.

If you are having trouble trying to pick the VST filter, then contact the support team for your engine’s brand.

team support

They should be able to guide you throughout the selection and even provide you with some recommendations. You can then select between them depending on your usage.

  1. Idling Problems

Aside from the sputtering and starting issues, your engine will also run into idling problems and will occasionally shut down. In most cases, you should change out the VST filter within 250 hours of operations.

Any longer than that and you will start running into these issues. So, if you can’t seem to put a finger on why your system is not idling properly, then there is a good chance that you’re dealing with the VST filter problem.

The only fix here is to install a new filter in your unit and then try operating the unit again.

Luckily a new VST filter won’t be heavy on your budget, and you can get a compatible replacement from any local dealer. So, make sure to reach out to local dealers and make a purchase of a new VST filter.

All in all, these were a few symptoms that you need to look out for when dealing with a clogged VST filter.

Most of these symptoms can overlap with other fuel pump issues, so try to narrow down on the issue by inspecting the VST filter. Otherwise, you will only be wasting your time.

  1. Faulty Parts On Vehicle

Now that you understand what problems a clogged VST filter can cause, there are some additional things that should be kept in mind.

People need to understand that the problems with their engine can be from a number of different reasons.

Some people might report that the VST filter on their vehicle gets clogged too fast.

Considering this, if you notice that the filters are running into issues before they pass their mileage then there are some other things that you need to look out for as well.

The most common reason behind the problem is usually the fuel you have been using. Making sure that you get this from a reliable source is essential.

As long as this is done, problems like these can be avoided. Other than this, some people can also get confused during the troubleshooting process.

The most common mistake you will notice people making is getting the fuel filter replaced while it was still in a good condition.

To prevent this problem, it is best that you inspect the other parts in your vehicle as well. There are several things that can be checked here.

If you are a beginner and checking these is difficult for you then it is best that you contact a specialist instead. They should be able to thoroughly check the engine and then provide you with the exact reason behind your issue.

You can then get the faulty parts replaced with new ones or get these repaired depending on the problem. Once done, your issue should be gone, and you no longer have to replace the VST filter.

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