Jim Rosinski wrote:

Are you saying the primer can't do its job (atomizing the fuel) unless
you're cranking while priming?

Yep.

Is priming without cranking the same as
pumping the throttle?

Sort of, but there are differences. Pumping the throttle squirts a jet of gas
into the carburettor. The primer ports are located further into the manifold. In
my engine, I have two and they are located immediately before two of the
cylinders. Priming while cranking causes the gas to be drawn into those
cylinders. Priming before cranking allows it to run down into the manifold under
the engine.

My plane is a tailwheel aircraft, and the carb is behind the engine, so pumping
the throttle basically puts a pool of gas into the manifold behind and below the
engine. Doesn't work for a cold start for me -- might for you.

George Patterson
The desire for safety stands against every great and noble enterprise.