Carburetor 172RG cuttlas

Hi all,

discussing Pelican's Perch #15: Manifold Pressure Sucks!

(
http://www.avweb.com/cgi-bin/udt/im....ry.id=1820 81
)

with some friends, we came to a point in the 172RG manual which says:

Starting engine
Mixture - RICH
Propeller - HIGH RPM
carburetor heat - COLD
Throttle - PUMP once or twice ??????

Does anyone know, wy to do that.
Does this carburetor has an accelerator pump like an carburetor for a car????
As far as I know an aircraft carburetor does not have such a pump. But
what other reason should that
pumping have??

Any idea?

Georg