In article jy67f.6582$%A1.1101@trndny01,
George Patterson wrote:
But pulling carb heat on, in the Cub, does definitely cause a decrease
in power.

The heat normally creates a rich mixture, which causes a decrease in power.


The reduction in power caused by the application of carb heat is mostly
due to the decrease in air mass flow through the engine, i.e. a
reduction in volumetric efficiency.



JKG