Breathe Easy: Taking Care of Your Motorcycle’s Air Filter
By Courtney Evans
Does your bike have a rough idle? Does is lack the performance that it once had? Does your bike lack some of the characteristics that actually drew you into the motorcycle lifestyle in the first place? All these things can happen when your bike isn’t properly maintained. Just like us, your bike needs to breathe easy.
In order for your engine to run at its best, it must have among other things, fresh, clean air. If your bike’s air filter is clogged and dirty, you will experience reduced gas mileage, power loss, rough idling, and host of other issues. Changing or servicing the air filter is an easy way to keep other bike systems operating at their best.
What does your air filter do?
An air filter basically traps particulate matter such as dust and dirt, and prevents it from entering into your engine. Typically, they are made of resin-impregnated, heat-cured “paper” that’s folded into pleats or the air filter can be made of foam. These pleats or foam catch and hold the dirt. Once these pleats and other surfaces are covered with dirt, airflow is greatly reduced. Thus, now your engine is not getting the airflow that it needs to run efficiently.
To illustrate my point, imagine that you were getting ready to take a quick 2 mile jog. For the first mile, you’re running strong and getting all the fresh air you need. Now for the second mile, I want you to tie a handkerchief around your nose and mouth like a bandit of the “Old West”. Your second mile is going to be miserable because your airflow is now restricted. Your lungs and your body will not be operating at their peak. I think that if you actually tried this, I doubt you’d ever neglect changing your air filter again!
Different types of air filters
There are several different types of air filters that you can use for your bike and they vary by manufacturer. As mentioned above, you have foam filters, paper filters, and pleated cotton filters.
Foam Air Filters are used in many types of small engines including lawnmowers, snowmobiles, and of course motorcycles. Generally, they are reusable, long-lasting, and efficient.
Paper Air Filters are generally used for OEM (Original Equipment Manufacturer) applications, meaning this is more than likely the type of air filter that your bike came from the factory with. They are also widely used for automobile OEM applications. They are typically pleated and may be reinforced with metal to help them hold their shape.
Some of the best types of air filters available today are Pleated Cotton Air Filters. These reusable aftermarket filters offered by K&N and BMC, bring the best in cost savings and longevity. Once in service, they could last the life of your motorcycle.
Cleaning or Replacing Your Air Filter
Depending on the type of bike you have, getting access to your bike’s air filter may be an easy affair or one that will take a little more effort. It may be as simple as removing the air filter cover on the side of the engine or you may have to remove the gas tank to gain access. Check with your owner’s manual to determine if you need to remove the seat or any other bodywork to get to the gas tank for proper removal. If you need to remove the tank, be sure to turn your petcock to the “off” position if you have one. No, I don’t mean “put the rooster in the barn”. Sorry, I couldn’t resist. If you don’t know what a petcock is, you probably don’t have one. Make sure you have some rags nearby to catch spilt fuel. Unbolt the tank and disconnect and label any wires or hoses to ensure proper reassembly. Again, consult your owners manual for specifics.
Once you have full access to the air filter, give it a quick blast with compressed air to clean dust and dirt from the screw holes before unscrewing it. Be careful not to drop any debris in to the engine compartment. If you drop a screw, use a telescoping magnet to fetch it. Once you’ve removed the air filter, cover the top of the air box with clean rags to keep the bad stuff out. Especially if the air box is going to be exposed for a prolonged period.
If you have a sponge-type air filter, you may be able to reuse it once or twice if it is good physical shape. Cleaning this type of filter requires a solvent (some kind of soap). You’ll need something that can break down any oil or dirt. Rinse clean and let it air dry. If the filter is in bad physical shape, replace it with a new one.
If your pleated paper-type filter is in good physical shape, you may also be able to reuse it once. I don’t recommend using this type of filter more than twice. Simply blow compressed air through the back side of the filter to clean it. Don’t wet it and be sure to keep it free of oil.
If you have an aftermarket pleated cotton filter, follow these steps to clean it. First you need to spray or pour solvent to break down the oil that is used to trap the debris. Let it soak for a while and rinse it from the back side of the filter. Then you need to let it air dry. You can sit it in the sun for a few hours or hang it in your garage overnight. A few words of caution, don’t use compressed air or a hair dryer to dry the filter. The cotton fibers will shrink and your nifty aftermarket air filter will be rendered useless. Next, you need to re-coat the cotton fibers with new filter oil. Don’t use any other type of oil and don’t over-soak the filter. A thin layer will do. If your oil uses a pour on applicator, pour it into the bottom of the pleats. Let the filter sit for a half hour and re-coat any areas that you may have missed.
Now, let’s put the filter back in. Installing a new or freshly cleaned filter is just the reverse of removal. The key here is to make sure that you have the right orientation. You must be facing due-north while you put the filter back in. Just kidding. In other words, the filter should face the proper direction for air flow. If the filter has a rubber o-ring, make sure it is in the proper position. Put the cover back on. If it has multiple screws, tighten them in an alternating pattern so that the cover pressure is evenly applied. If you removed your gas tank or other body panels, you can re-install them now. See how easy that was?
To keep your motorcycle breathing easy, just get into the habit of changing out or cleaning your air filter once a year. Change it at the beginning of the riding season, every season. Your bike will burble, scream like a banshee, or purr like a kitten when you ask it to perform. I can see you grinning from ear-to-ear already. Let’s ride.