Good question. I have wondered the same thing. Seems Husqvarna and Stihl are the leaders in the chainsaw world and it follows that their engines would make good conversions. They say chainsaw engines are powerful, lightweight, and well-built anyway. The problem may be due to lack of volume/popularity and the ability to acquire one cheaply enough to make the conversion worthwhile. I have a Husq 335xpt, but need it much more as a saw than an aircraft engine. Stripped down a Ryobi 31 cc and have an old Stihl trimmer 25.4 cc that I will tear down next. Whichever offers the best prospect I will use in a 90 size spitfire...

I am interested in seeing the response to this thread...