Keeping your engine supplied with plenty of fresh air is essential to it running at it’s full potential – yet maintaining your air filter is one of the most often overlooked parts of motorcycle maintenance! Check out our guide to how to maintain your air filter to keep your bike breathing easy and running at its peak performance!
One of the least glamorous parts of doing regular maintenance on your bike is your air filter. They’re not as sexy as a new set of tires, or as essential oil changes (heck, a lot of people don’t even realize you’re even supposed to change them at all!)
But if you care about having a well-running machine, taking care of your air filter is essential – it’s the gatekeeper between your engine, and the fresh air it needs to burn fuel and create power. Best case, it will be dirty and choke off some air, robbing your engine of power; worst case, if damaged, it will let particles right into your combustion chambers! Taking care of your air filter is pretty important when you think about it.
So to help you out, we’ve prepared this guide on how to get the perfect air filter for your bike, and then we’ll show you how to take care of it so you get maximum performance and life out of it. Don’t let your bike get motorcycle-emphysema – take care of its air!
Types of Motorcycle Air Filters
First off, lets cover the basic types of air filters there are out there on the market, and narrow down your search to the right one for you. There are three main types of filters for motorcycles: paper filters, foam filters, and cotton filters.
The Hiflofiltro Air Filter is a basic air filter that will work as a perfect stock replacement.
Most street motorcycles come stock with a paper filter like any of these BMC Replacement Motorcycle Air Filters. Many people like paper filters because they are inexpensive and disposable. There is no cleaning involved whatsoever. In fact, you CAN’T clean them; doing so will just break it down and damage it, rendering it useless. When these are dirty, they get tossed, and a new one takes its place.
But while they do their job just fine in most applications, some believe that these types of filters fail to actually remove a whole lot of the particulates from the air that you don’t want entering your engine. If that sounds familiar to you, it would probably be better for you to spend the extra money on a higher performance foam or cotton filter.
The UNI Multi-Stage Competition Air Filter
Foam filters are typically stock in off-road bikes. Unlike paper filters in street bikes that have to be replaced, foam filters can be cleaned and reused, which makes them pretty inexpensive compared to paper filters in terms of lifetime value.
But while paper filters are sometimes accused of not blocking enough particulates, foam filters have been said to not allow enough air flow, especially as they get dirty. Foam filters are indeed denser which means that they do let less air in, but this is essential for effective filtration, especially in the dustier, dirtier environments where they’re often used.
The K&N Custom Clamp-On Air Filter looks as good as it performs, and is also a great dress-up item for your ride.
The last option, a cotton filter, is the most expensive of the three, but there’s a reason; they not only flow more air for better performance, but they can be cleaned and reused for hundreds of thousands of miles. If a cotton filter is properly maintained, it can easily outlast even your engine itself, which is why many say that one of these filters is “the last one you’ll ever have to buy.”
Cleaning a cotton filter tends to be a bit more complicated than its counterparts though; some will require a special cleaning fluid and oil in order to stay at their peak. Most filter manufacturers have kits of all of the right cleaners exactly for this purpose, so that when it comes time to clean and re-oil your filter, you can get everything you need in one shot.
If you want to really go all out, you can get a full air cleaner kit for your ride, like this one from Kuryakyn. Pricey, but they will make a big improvement in looks and performance.
Checking and Cleaning Motorcycle Air Filters
It’s a good habit to check your air filter every time you change your oil, or after a really dirty off-road ride to see if it’s in need of a replacement or a good scrub down. As mentioned before, a paper filter will just get tossed and replaced when necessary, but foam or cotton filters can be washed, re-oiled and put back in when they’re starting to look dingy. It’s important to do this the right way, however, or you’ll risk damaging the filter and making it completely ineffective.
Cleaning Foam Air Filters
To clean a foam filter, start by removing it from its housing (if you’re not sure where it is located or how to remove it, check with your service manual as each bike varies). Once you have the air filter removed, we recommend blocking the air inlet with something to prevent any debris from entering your engine accidentally (usually stuffing a clean rag into the inlet will do the trick.)
In order to properly clean foam filters, it’s important to use the correct chemicals. Using a chemical that is corrosive can break down the glue that holds the filter together, and any soap that leaves behind a residue can prevent the filter from being able to flow air adequately. Many filter manufacturers have special kits ready to go, like this Motorex Air Cleaning Kit, to make sure you’re getting all the right supplies in one shot.
Once you’ve got the dirty foam filter free from the housing, slap on a pair of these BikeBandit.com Nitrile Worx Performance Gloves and knock the loose dirt and crud free from the filter, then apply the air filter cleaner and massage it in thoroughly. Avoid wringing or stretching the filter as they are easy to rip or damage. A good gentle kneading will do just fine. Once the cleaner has worked its magic, rinse the filter from the inside out with warm water.
Next, fill up a wash bucket or tub with warm water and a mild soap such as dish soap. In order to get any residual dirt out after you’ve used the foam cleaner, wash the filter in the soap and water solution, rinse and repeat three times. This should clean out any remaining debris and filter cleaner residue.
Cleaning out your air filter can be pretty nasty if it gets hard use – but if you don’t do it, all that gunk and grime will be choking off your bike’s air supply, killing it’s performance!
When the filter is back to the color is was when you first put it in your bike (and your soap water is the color of an MX track) gently squeeze out the excess water. Still refrain from wringing out or stretching the filter to dry it, because that can damage it. With the excess water back in the wash tub, set your filter aside to dry.
Once the filter is COMPLETELY dry, check to make sure the airbox is clean. If it is, you can begin to saturate the filter with fresh filter oil. Be sure to get the entire filter including the sealing flange and lip. Then squeeze out the excess as it will make it hard for air to flow through the filter. We also recommend applying a fair amount of some sealing grease to the sealing flange before popping it back into its housing, like this K&N Sealing Grease or some No Toil Rim Grease. After that, you’ll be good to go!
Cleaning Cotton Air Filters
Start by pulling the filter from its housing and removing any excess debris. With the appropriate filter cleaner, apply liberally and let it sit to do its magic for a few minutes. Once its had a chance to break down most of the dirt and grime, rinse the cleaner off from the inside out to help the dirt and cleaner make its way back out of the layers of the cotton fibers. Next, fill a bucket or wash tub with warm water and a mild soap and swish the filter gently around in it to clean out any remaining dirt and filter cleaner. Rinse and repeat.
With the filter now free from dirt, it’s time to let it dry. Just as with a foam filter, you’ll want to give a cotton filter as long as it needs to COMPLETELY dry, as you won’t want any moisture getting trapped in it when you oil it and put it back on your engine. Don’t try to accelerate the drying process with compressed air, because it can damage the filter very easily.
Once the filter is dry, apply fresh air filter oil, like this K&N Air Filter Oil. When doing this, it might help to use one from an aerosol can rather than from a squeeze applicator in order to get an even application. Wipe any excess oil from the filter and put it back in its housing.
Air filters are an important part of a motorcycle engine, but they are overlooked way too often. To keep your bike running in top shape, be sure to check your filter as often as you change your oil, and if you’re doing a lot of off-road riding or ride in very dusty conditions, you should actually check your air filter after every ride. Riding with a clean air filter lets your engine breathe easily, rev faster, and make maximum power – and those are thing that make every rider happy!
To check out our full selection of air filters and cleaning products, check out our Air Filter Section!