Re: Why ar they so sooty and what is that hairy stuff?
Whoops! "A third is incompletely combusted" is incorrect, since what I mean is "there's enough oxygen to completely combust two thirds of the fuel" and they're not the same.
Anyway at an O:F of 2.3:1, the stoichiometry of C:H:O is 1:2:2, so (again, assuming no mistake in the calculations) under ideal circumstances you can go completely to H2O + CO, or completely to CO2 + H2. Or, as we see, several species (probably even some O2) including free carbon to complicate matters.