why is rich better for power ??

[Bill Williams]

	You may get a real earfull on this one!!! IMHO it is due to the
cooling effect of the excess fuel as well as the ability of a rich
mixture to burn all the air in the cylinder. Second order effects might
include a higher  heat release from a partial burn of more fuel. As we
are O2 limited just burning the hydrogen off the fuel might give more
heat.
---                                   Bill in Boulder   "Engineering as
an Art Form"                                ---