Dirty air filters cause sluggish engine operation resulting in loss of power, poor starting and excessive fuel consumption. Changing the filter on your Stihl weedeater will get your Stihl running efficiently. Depending upon your model, the air filter housing may have a screw securing the cover to the housing. Replacement filters are available at Stihl dealers and home improvement centers. You will need your model number when purchasing a replacement filter.
Grab the spark plug wire boot with your fingers and pull it off the spark plug. Bend the spark plug wire around the side of the engine to prevent the boot from contacting the spark plug accidentally.
Set the choke lever on the Stihl weedeater to the neutral position. The choke lever will be near the carburetor and air filter housing on the left side of the engine.
Pull the air filter housing cover off the air filter. Your Stihl may have a screw in the center of the housing cover which you can remove with a Phillips-head screwdriver. Some models will have a tab on the front edge of the cover. Press the tab in with your thumb and the cover will swing open.
Clean any loose dirt and debris away from the filter with a clean cloth. Pull the filter element out of the housing. Clean any loose dirt from the base of the housing with the clean cloth.
Place the new element into the housing. Reattach the cover either by closing the cover and snapping it shut or attaching the cover with the retaining screw.
Push the spark plug wire boot back over the spark plug. Push the boot with your fingers until it locks into place.