I ran the Homelite 25cc Glow in the inverted position. It starts with one flip after running. I see no problem whatsoever with it inverted. May have even run better. I do have to get a muffler on her. It does not hold the heat of the glow and will stop on a idle. If I cover/block the exhaust port she runs smoother and does not quit then. The same in all 3 positions...even sideways. Electric starter always gets it going in right direction. Although in the invert position... it seem to start and run the right direction by hand flipping. Go figure??? More tests later. Capt,n