Harley Fuel Filter Symptoms (9 Things To Be Aware Of)

How frequently have you considered replacing your Harley Davidson’s fuel filter? Before having such sentiments, what signs of a failing fuel filter should you watch out for?

A gust of wind oozes out of your Harley’s air filter, the engine eventually runs rough, and there is a lot of sputtering and spitting.

Still, most Harley Davidson motorcycle owners have no idea what a fuel filter failure on their motorcycle means, let alone know what to do in such a situation!

Harley Fuel Filter Symptoms

Harley Davidson’s fuel filter symptoms are similar to faulty fuel pump symptoms. These include failure engine start, those random cylinder misfires, and engine stuttering issues. In addition, you’ll start to notice strange or erratic RPM reading from your tachometer. You’ll also hear loud noises from your fuel tank and engine performance issues. 

Still, want to know the other symptoms of your Harley Davidson fuel filter? Here are nine things to be aware of. Stay tuned!

1. Failure To Start  Your Motorcycle

Your engine not starting is one clear sign that your Harley fuel filter may be defective. Also, the fuel pressure may find it challenging to overcome the volume of grit in your fuel filter.

In addition, gasoline impurities stop the fuel pressure from pushing items and powering the engine. When the gasoline filter is unclean, your engine may snap but won’t start.

2. Unusual Cylinder Misfire

Another sign of a failing fuel filter in a Harley Davidson is that the engine cylinder begins to misfire when the bike is under a lot of strain.

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For example, the motorbike could spit or stutter while climbing a slope, even though this might be an error code.

Further, cylinder misfire is often caused by some additional fuel reaching one or more injectors, which results in the cylinder misfiring.

But you should note that a blocked fuel filter on a Harley Davidson motorbike would only result in sporadic engine misfires when running and not when you stop the motorcycle.

3. Engine Stuttering Issue

When your Harley motorbike sometimes stops running when under load after starting and running for a while, your fuel filter is most likely unclean.

In addition, your motorbike may start up correctly and allow you to travel a few miles, but because of power loss, the engine may repeatedly stop while you travel.

So, the volume of gas given to the engine decreases when the engine stalls more frequently, primarily because of the numerous contaminants found in your fuel filter.

4. Strange Or Erratic RPM Reading

Your gasoline filter may need to be changed if the engine of your Harley Davidson motorbike idles erratically, which frequently displays a decrease from the typical revolutions per minute (RPM).

A functioning Harley Davidson motorbike typically operates at 400 and 800 RPM. If you notice that the tachometer gives you irregular engine speed readings, your fuel filter may be malfunctioning.

5. Loud Fuel Pump

Loud Fuel Pump

The fuel pump must work harder to circulate the gasoline when there is a clog in the fuel line.

Additionally, the gasoline pump struggles because of the higher pressure in the fuel line caused by your Harley Davidson’s clogged fuel filter.

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So, if you place your ear close to the gasoline cap, the fuel pump will often emit an audible whining noise.

6. Weak Acceleration Is Experienced

If you’ve had the motorbike for a while and notice a decrease in engine power, the fuel filter may be blocked. However, your Harley may function adequately in city traffic.

Still, the dirty fuel filter prevents the necessary amount of gasoline from passing when the motorbike is driven at high RPMs for an extended period on the highway.

Therefore, inspecting the fuel filter for dirt after you’ve examined the mass air flow sensor, spark plugs, and the air filter is a great idea.

But, of course, low oil pressure or a defective EGR valve might also be to blame for this.

7. Engine Performance Issues

A blocked fuel filter may lead the engine to erratically surge, spit, or hesitate when operating under solid loads. Accelerating, particularly going up a steep hill, tends to make this more noticeable.

Of course, under typical driving circumstances, there could be no symptoms, but a blocked fuel filter will deprive the engine of the extra fuel it needs while accelerating quickly.

The amount of the fuel limitation brought on by a filthy Harley filter will determine how shaky or stuttery an engine is.

8. Breakdowns Of Fuel Systems

A constrained fuel filter may be the root of a loud, damaged, or failing fuel pump. The proper amount of gasoline can’t get to the engine if the fuel filter is blocked.

In addition, a poor Harley Davidson fuel filter will cause the fuel pump to attempt to make up for it, putting too much strain on the pump’s motor and causing it to break down too soon.

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Contaminants bypassing a filthy fuel filter can harm, clog, or even result in a fuel injector leaking, which can create various drivability issues within an engine.

If not wholly failed, removing a clogged fuel filter and having the injectors serviced or flushed by experts should immediately solve the problem.

9. Harley Davidson Engine Stalling

If your Harley Davidson engine frequently stops driving, your fuel filter may be unclean.

But, given how awful the obstruction was, your motorbike could start up again with no apparent loss of power.

Further, stalls increase in frequency or get worse when accelerating as the block gets worse and fuel supply becomes more erratic.

Therefore, it’s probably time to change the filter because it is completely blocked.

To know more, you can also read our posts on Harley fuel pump symptoms, how long Harley Davidson tires last, and why motorcycles are better than cars.


Don’t put off having electrical and mechanical inspections on your Harley Davidson bike until it breaks down. Likewise, you don’t need to wait until the fuel filter is blocked with junk before cleaning it.

Instead, try changing the filter as soon as you become aware of any engine problems linked to the fuel filter, even if it hasn’t been used for months or years.

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