RE: Do you suggest the OS FL-70 4str.?
I'm also an admirer of the simplicity and surprisingly good performance of a well-designed air-bleed carby.
The only engine I've still got with an AB carb is my TT42GP and that thing will idle all day at just a tick-over, then give full power in an instant without loading up or hesitating -- which is more than I can say for a lot of cheap Chinese twin-needle-equipped engines.
A good twin needle carby has the potential to out-perform an airbleed unit but so many of these rotten twin-needle carbs (such as the SuperTigre, SK and some GMS units, etc) are just so poorly designed that they give inferior results.