It is a matter of differing rotational speeds. When the engine is not running/stationary the starter turns and the sprag clutch catches to the then non-moving crank. Once the engine is running the crank is spinning much faster than the starter can ever go so there is no lockup with the starter, the starter is just free spinning, the engine crank is out running the starter spinning in the same direction as the starter. When the starter goes faster than the crank it will lock up to it i.e. when the crank is not moving. But yes the starter is still spinning if the relay contacts are closed.
Have you ever attempted to pull the pull cord on a running lawnmower, there is nothing, you just pull against the wound spring. If it was possible to pull it quick enough you would catch up and lockup again, but you can't pull it quick enough. A pull start and a sprag clutch perform the same function.
05 1300R -sadly sold 04 BMW K1200LT - Luxury Tourer, smooth efficient quiet power,sporty mile eater 05 BMW F650GS - rugged and elegant adventure tourer, does it all well, high speedcruising to rough dirt roads
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