Here is a quick video showing how I like to clean the exhaust screen / spark arrestor in my Stihl 2 stroke weedeater / line trimmer. The model in this video is the FS 55 R but this guide applies to just about any machine out there, fs 36, fs 38, fa 40, km, km90,...
Km110
How to fix a gas leak on a Stihl KM110 trimmer/edger unit
How to repair Stihl KM110 Trimmer/Edger Unit