Al Patrick fired this volley in
netofbeaufortcounty:

, centrifugal force moves the spring loaded
bendix forward and engages the fly wheel teeth which turns the
engine
to initiate the start.

And of course, just like "Mythbusters", Gil's Garage was sometimes
wrong.

It is not centrifugal force, but the inertia of the pinion that keeps
it from spinning, while the shaft with helical groove spins under it,
propelling it toward the ring gear.

LLoyd