K&N air filters, or should I say aftermarket air filters could just be the most common first installs for motorcycle enthusiasts – the installation is easy and it’s not so expensive too!
I am assuming you already know how aftermarket air filters work – they are less restrictive and thus allow more airflow for more power.
But how much horsepower can you get really? Are they worth the price? (about $50 – $100 depending on your motorcycle model).
In this article, I will talk about what exactly aftermarket air filters do, their pros, their cons and finally wrap it up with my thoughts on whether they are worth it or not.
TLDR – At the price of $50 – $100, K&N air filters are worth the money because they are reusable, long lasting and improve the air intake on your bike.
However, don’t expect to gain any horsepower just from installing a K&N air filter.
Do you have more questions? I hope so! Because there are so many more things to talk about. Let’s begin with how aftermarket air filters work and why an improved airflow is good.
Key Takeaways In This Article:
- K&N Air Filters are long lasting and reusable
- K&N Air Filters alone don’t provide performance gain
- K&N Air Filters don’t change motorcycle sound
- K&N Air Filters work best when paired with performance exhaust
- K&N Air Filters are worth it because they will save you money in the long run
What Really Happens When You Install Aftermarket Air Filters?
If you don’t already know, motorcycles use a combustion engine – which means it uses a mixture of air and fuel to create combustion and generate power. This happens in the combustion chamber.
When combustion is created, it also generates exhaust gases – which must leave the combustion chamber as quick as possible to give room for air in the next combustion cycle.
If you want more horsepower, you need a bigger combustion – which means you need more air and fuel. Fuel is injected by the fuel injector and can be made to inject more by tuning.
Getting more air is the tricky part. This is where aftermarket air filters come in. They are less restrictive than stock – allowing more air to enter into the combustion chamber (for the sake of creating more power).
K&N motorcycle air filter
Knowing this, the next question becomes “How much extra power is generated by aftermarket air filters?”
The answer is not much. In fact, if you are only installing aftermarket air filters without any other performance mods like exhausts, then you will not get any extra power at all.
The airflow changes made from aftermarket air filters are not significant enough to generate extra horsepower for your motorcycle. They should be installed together with a full system exhaust.
This way, you maximize the potential horsepower provided from the exhaust. So is K&N air filter still worth the money? What else are they good for? Let’s find out.
Motorcycle full system exhaust
Why K&N Air Filters For Motorcycles Are Worth It (The Pros)
1. Improved airflow
This is the point we just discussed above. Aftermarket air filters like K&N are less restrictive than stock air filters – which means they allow much more air to enter the combustion chamber.
This increased airflow can help with generating a bigger combustion and more horsepower. However, the increased airflow from an aftermarket air filter alone is not significant enough to get more horsepower for your motorcycle.
You need to pair this up with other performance mods like a full system exhaust to actually feel the horsepower gain.
2. Reusable
K&N air filters are reusable – which means you could actually take them off and wash the dirt away and install it right back. No new air filter needed!
Though, you should wash it with K&N’s cleaning kit for about $15. It comes with the cleaner and oil. (Aside from just cleaning, you also need to re-oil your K&N air filter.)
K&N Air filter cleaner
3. Long Lasting
K&N air filters can go up to 50,000 miles before cleaning is required. This figure comes from their blog. For motorcycles, I don’t think you should wait that long before cleaning them.
Generally speaking for motorcycles, you should wash your K&N air filters after about 10,000 miles or so. This also depends on your driving condition. If it’s not super dusty, you could even go longer.
My advice is to check the condition of your air filters every time you change the oil. If it looks dirty and needs cleaning, then you should clean them.
4. Great Starting Step For Enthusiast
A K&N air filter is a great first mod for an enthusiast. They are not that expensive and are quite easy to install.
Is this your first mod? If yes, then I would say go for it! And make sure you install it yourself. It should be done pretty quickly. K&N air filters usually come with an instruction manual.
Cons Of K&N Air Filters For Motorcycles
1. More Dirt Getting In
Less restrictive air filter is good for air flow but it’s also worse at actually filtering. Aftermarket filters like K&N will allow more dirt to get inside your engine.
This includes things like dust, sand and even insects. In theory, this can cause engine failure. Especially when the dirt builds up over time.
However, K&N air filters use special oil to trap these impurities while allowing only air to pass through. I personally have never heard of anyone having an engine breakdown due to K&N air filters.
So you should be safe but just know the risks.
2. No Significant Horsepower Gain
Installing K&N air filters alone will not give any extra horsepower to your motorcycle – the increased airflow is not significant enough to impact anything.
Aftermarket air filters like K&N are best used with other performance mods like performance exhausts.
Install a full system performance exhaust, K&N air filter and bring your motorcycle for a tune (Power Commander or ECU flash tune) – I promise you will feel the performance gain.
Aftermarket air filters are not the right mod for performance.
Do You Need To Tune After Installing Aftermarket Air Filters?
You don’t need to tune your motorcycle after just installing an aftermarket air filter. As I said, the change in airflow is not significant enough to change anything.
If you are thinking of tuning because you are afraid of running lean or afraid of damaging the engine, then don’t worry about it and don’t tune.
But if you are thinking of tuning to customize the behavior of your motorcycle (like throttle response and removing rev limiter), then go ahead!
Though, I would recommend you install a full system exhaust first, then install the K&N air filter and then only bring your motorcycle to a tune. This way, your performance exhaust will work at it’s full potential to give you power.
I have an article here where I discuss much more about tuning. Things like the cost, different types and when should you really do it. How Much Does It Cost To Tune Your Motorcycle?
Will K&N Air Filters Damage Motorcycle’s Engine?
Like all things aftermarket, there’s always risks of damage. However, what are the odds that it will actually happen?
In theory, K&N air filters could let more dirt and impurities into the engine – which could build up and cause wear and tear damages. Or worse, engine failure.
Also, because of the increased air flow, K&N air filters can cause your engine to run lean (if no tuning is done).
But these are just in theory. In practice, you won’t have any engine failure, nor will your engine run lean.
As advertised, K&N air filters make use of oil to trap only impurities and allow air in. Which means, dirt will not build up to the point where it becomes dangerous.
And also, the change in airflow from K&N air filters are not significant enough to cause your engine to run lean. Therefore, you won’t need tuning and your motorcycles engine will likely not fail! (At least, I haven’t heard any such story).
Will K&N Air Filters Improve Your Motorcycle Sound?
No, K&N air filters won’t change the way your motorcycle sound. The air filters in motorcycles are too small to change the way your motorcycle sounds.
This is only true for cars (not motorcycles). In cars, you could install cone-shaped K&N air filters that are more exposed, big and less restrictive.
Installing it will change the way your car sounds when it accelerates. But not on motorcycles! Don’t install an aftermarket air filter for the sound. For a better sound, look into getting a slip-on or new baffles instead.
Conclusion
So, after all that info – are K&N air filters worth it? I think for its price of about $50 – $100, it’s absolutely worth it. You are going to save in the long run.
The pros are real – they are indeed reusable, washable and last long. Just don’t go buying a K&N and expect to get 5-10 horsepower from your motorcycles – that won’t happen.
The cons are all theory. In practice, it’s not as bad as it sounds and I have never heard of anyone who has engine damage due to aftermarket air filters.
I hope this has been a useful read to you!
