How Do I Know If My Fuel Filter is Clogged?

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Clogged fuel filters have a negative impact on the health of the engine. 

Does your lawnmower engine stall when accelerating or does it splutter? 

If your answer to these pressing questions is affirmative, then your fuel filters are bad or clogged. This article talks about the signs of a clogged fuel filter.

Ready? Let’s dive right into it:

6 Signs of a clogged fuel filter

1. Smelly Fumes

This is one of the signs of a clogged fuel filter.  Bad or clogged fuel filters will make your engine produce exhaust fumes with a foul smell. 

If this is the case, then you need to clean them. You can also replace them if it becomes necessary to do so.

2. The Engine Fails to Start


Clogged filters may cause your engine not to start. Whether the engine jerks or fails to start, inspect the fuel filters for partial or complete clogging.

3. No Engine Power

Clogged fuel filters can disable the free flow of fuel to the injectors, causing the engine to lose power.  The simple fix to this is to park the mower and check the filters for clogging. 

If you make use of a modern mowing machine, you will see an error code on the dashboard. This usually occurs when the engine goes into limp mode. 

Although, it is advisable not to overrule the possibility of defective injectors and other parts that connect the filters to the engine and carburetor.

Sometimes, injectors may give you a wrong sign about clogged filters whereas that isn’t the case. 

That is why it is important to carry out a proper diagnosis on other parts that connects the fuel filters to the engine and carburetor.

4. Lawn mower engine stalls when accelerating


When accelerating, more fuel goes through the filter and into the combustion chamber. If you notice that your mower’s engine loses its power and stalls when accelerating, it might be as a result of a bad fuel filter.

Clogged filters prevent adequate free flow to the engine, causing it to stall when mowing at high speed.  It is advisable to check your mower for debris and other particles such as dust and rust.

5. The Engine is Misfiring Randomly

Another symptom of a clogged fuel filter is when the engine starts to misfire. This means that the injectors are not getting adequate fuel. All you need to do is to diagnose the filters for clogging.

6. Physical Diagnosis of the Fuel Filter


You can also know the signs of a clogged fuel filter if you physically diagnose your lawn mower. All you need to do is to blow air through the fuel-in-nozzle.

The fuel filter is clogged if air does not come out through the fuel-out nozzle. If you notice this, then it is important to clean or replace it.


Clogged fuel filters can jeopardize the health of your lawn mower engine. That is why we have outlined the signs of bad or clogged fuel filters to further prevent engine damage. 

To ensure a sufficient supply of clean fuel, it is advisable to regularly clean or replace clogged fuel filters.