In any case, it’s money thrown away needlessly, not to mention that engine damages caused by dirty air filters aren’t covered by ANY warranty.

Ok, now that I’ve made my point about the need for frequent servicing of air filters, let’s take a look at the “how to” side of things. Servicing an air filter is neither a hard or time consuming task and I’ll try to guide you with some very generic procedures. Once again, let me point out that should the engine manufacturer suggest a different procedure, your best option will be to follow those instructions.

Frequency of Service
In a pinch, I would recommend that the air filter be checked approximately every two to three hours of usage, with service at a minimum of every five hours of use. In dustier conditions you probably should at least check it more often. If it looks dirty after an attempted cleaning, chances are it’s time for a replacement.

Foam Filters
Before you service the filter, first check to see if it is abnormally dirty and to test the condition of the foam material by squeezing it and turning it loose. It should quickly return to it’s normal size and shape. If it doesn’t pass both tests, you may want to replace it rather than service it.

1. After removing the filter, wash it thoroughly using warm soapy water.
(Your favorite brand of dishwashing liquid should work well for this.)

2. After you’ve gotten it clean, the next step is to rinse all the soap out.

3. Squeeze out the excess water and blot dry with a paper towel or old cloth. If it’s hot, you might want to take a break and give it a little time to air dry.

4. Once the filter is clean and dry, apply about a tablespoon or so of clean 30 wt. motor oil, work it into the foam thoroughly, and blot any excess with a paper towel.

Your done!

Be sure to wipe away any dirt or debris from the container that holds the filter before reinstalling it.

Paper Cartridge Filters

First of all, be aware that on some engines, the air flows in from the underside of the filter, so you may need to remove it to see just how dirty it is. A quick glance from the outside may overlook a mess underneath.

Pre-cleaners
Many engines built today will have a thin foam pre-cleaner installed in front of the paper cartridge filter and if serviced frequently, not only it will help protect the engine, it will also extend the life of the paper filter as well. Service procedures for the pre-cleaner are basically the same for the foam filters shown above.

1. Remove the air filter and separate it from the pre cleaner if so equipped.

2. Tap the paper filter on a solid surface in order to shake loose the heavier deposits.

3. If the filter is not too dirty you can use compressed air from the back side of the filter to blow the remaining dirt from the pleats of the paper element.

Yes, that SOUNDS like a lot of time and/or work, but it really doesn’t take more than a few minutes to insure that the engine is properly protected. Since air filters are so important and aren’t very expensive, it’s not a bad idea to keep one on hand as a spare.