I might have used one of the Briggs engines you mention MF but I don’t remember it. Probably like my experience with the Honda four strokes: nothing to complain about, a good motor but I find the two stroke better on a push mower.
Most of mine are full cranks with g3 carburettors. I have one full crank on a g4/LM and have kept one powertorque engined mower. The full crank motor feels stronger to me. I haven’t done any sort of scientific testing to prove it though.
I have a few early 70’s utilities and these are extremely light weight. I’m actually quite fond of the 125cc model, there’s a certain sweetness to that engine. In my applications I don’t use substantially less fuel with a 125 than with a 160 though. I haven’t noticed the powertorque using more fuel than the full cranks but that doesn’t mean there’s no difference in fuel consumption, probably just that it’s not notable in my setting.
