Gotta be careful making a blanket statement like that
Neither do at least 2 of the four strokes that have NO oil in the crankcase, Shindaiwa 25, 34, and 80cc, and Stihl 64.9cc..
I converted these...[8D]
Stihl also has a few smaller engines, I have not converted those....
So far they all run about like a G23 except the 64.9 Stihl, it is close to a G62 in performance...And weight..