Pardon the Interruption..(Apologies to Tony Kornheiser and Michael Wilbon)...

At the risk of sounding stupid, it sounds to me like Larry is saying that when the mixture is too rich, the combustion has a tendency to produce heat rather than force. I did not glean from his take, that the fuel was necessarily unburnt.

I think I remember reading somewhere that diesel engines convert a higher percentage of the stored energy in diesel fuel, than gasoline. Something like...

Diesel 37% force (motive power), 63% wasted (I'm assuming largely heat)

Gasoline 25% motive power, 75% wasted.

So, if I put these two together, it sounds like Larry is saying that when the mixture is too rich, the ratio of motive power to wasted energy starts to drop down from 37%.

Or did I dream all this last night?

__________________
MB 1986 190D in my past
MB 1987 300E on the street
MB 1994 'Smoke Silver' E420 in my driveway
1999 Mazda Miata in the fun stable
1964 E-Type Jaguar Coupe- Sold
1970 E-Type Jaguar Coupe- Sold
1968 Corvair Monza Conv. with Turbo Transplant- Sold
1986 Merkur Xr4ti- abandoned
various mundane American autos

If I'd known then what I know now...

Hell, I'd probably still have done it anyways.