Filthy Filters Will Mess Up Your Ride

What you need to know about staying clean

By Jasmine Bluecreek Clark

Nearly all internal combustion machines like our motorcycle engines have filters to help keep the machine running well. Many electrical machines also have air or other filters. The filters are there to help keep pollutants, dirt and other unwanted stuff out of the engine. If the filters should become clogged or blocked they cannot do their job of filtering out the bad stuff.

With this in mind we should be checking, cleaning or changing our motorcycle engines filters regularly. Most motorcycles have at least an air filter and an oil filter. Many models will also have a fuel filter in the system. All filters need to be cleaned or replaced on a regular basis. How will you know when to check or change them?

A variety of air filters; only one will fit your motorcycle.

Fuel filters that are in the gas tank will usually be connected to the fuel pump assembly and should be handled by a trained mechanic. On hybrids and custom built motorcycles, there may also be other filters installed. Some customized motorcycles, which have incorporated automobile engines, such as the Chevy V-6 and Chevy V-8 engines, may also have a transmission filter. All filters need to be cleaned or replaced on a regular basis. So, the next question is how will we know when to check or change them?

Generally, you can discover where these filters are located by reading your motorcycle owners manual. There should also be information in the owners manual which tells you how often the manufacturer recommends checking or changing the filters. I check my motorcycle filters more frequently than the manufacturer recommends. If you follow that advice, you may never need this next piece of information.

Dont leave town with a dirty air and/or fuel filter; always want to check them before a long road trip. In most cases, replacing or cleaning your filters is an inexpensive proposition and ensures that the engine will be able to run “clean” while you are out on the road.

Air filters can be usually visible like this one located on the outside of the engine on a Harley-Davidson; or they can be hidden under the seat or gas tank, or even behind the engine.

Your motorcycle will tell you when youve let the preventative maintenance slide for too long. Clogged air filters can cause a variety of obvious symptoms. If the engine isnt getting enough fresh air, it will run too rich as evidence by black smoke coming out the exhaust pipes or the carburetor (if you have one). Another symptom of a clogged or dirty air filter is spark plugs that foul out (dont work). The worse case scenario is your motorcycle flat wont run if the clean air is choked off: Read – stall city!

Air filters come in all shapes and sizes. Here#39;s a cone style custom air filter.

The same kind of result can occur with a filthy fuel filter, that is, if the flow of fuel to the carburetor or fuel injectors is blocked. Your motorcycle will not run. It may cough and sputter and appear to be out of gas even though you can see plenty of gas in the tank.

Fuel filters come in two main styles: inline and internal. An inline fuel filter is found in the fuel line between the petcock and the carburetor or injectors. An internal fuel filter is inside the gas tank connected to the fuel pump assembly and should be handled by a trained mechanic.

Inline fuel filters are usually easy to find and see like on this Harley-Davidson.
You can see how this one on a Kawasaki is held in with simple screw clamps, easy to remove and replace.

Oil filters should be changed every time the oil is changed. Engines will run for quite a long time on old oil without such dramatic effects as stalling the motorcycle, but this does not mean its good for the engine. Regular oil and oil filter changes are vital to a healthy engine. Check your owners manual for the recommended time period between oil changes.

This oil filter on a Harley-Davidson is located in the front of the engine.
Oil filters come in many shapes and sizes. Be sure to pick the correct one for your motorcycle.

Oil, fuel and air filters do a great job of protecting our motorcycles engine. Just think if all that stuff the filter collects is bad enough to choke off air, fuel or oil flow how bad would it be if all that stuff actually made it into the carburetor, fuel injectors, or engine?

When it comes to filters, I suggest following the motorcycle manufacturers recommendations to get the best results. There is more information and some helpful hints on the subject of filters in my book, “ABCs of Motorcycle Wrenching,” Chapters 5 and 9. (Read WRNs review.)

About the Author

Jasmine Bluecreek Clark first threw a leg over a motorcycle at age 12. She took time off from riding to raise a family, starting back up in 1995 and logging more than 100,000 miles on her street bikes. With a background in auto mechanics, she became ASE certified in automotive brake systems in 1999. She is an MSF instructor and became a specialist in teaching deaf and hard of hearing riders to learn to ride garnering two MSF National Awards for her efforts with these classes. Jasmine has written two books, “ABC’s of Motorcycle Wrenching” will give the novice rider or mechanic a basic understanding of how their motorcycle works; and “Women In The Wind, Fearless Women of the 20th amp; 21st Centuries” tells many entertaining, genuine riding stories from female riders from the 1930s to 2005. Visit for more information.

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