Bendix rotation over shaft: what can cause overspin?

Question

The engine I have rebuilt (Skoda Estelle, '72, RWD, rear mounted engine), came with a starter that has a curious behavior, at least to me: when I apply power to it, correctly engages the flywheel and do its job, however, when I turn it off, I can hear it still free spinning for a few seconds. It is like it keeps spinning by inertia until it stops by itself. It is not an electrical issue. This is specially annoying because I need to wait for it to stop spinning before trying to crank again, or it will not synchronize well and "rasp" the sprocket vs flywheel.

So my question is: wouldn't it be the bendix too "loose"? I mean, the bendix spins together with the shaft which also synchronize it vs the flywheel using the helicoidal grooves...I wonder if the bendix should be "stiff" itself and allow rotation only from the axle. In this starter, the bendix behaves like a cricket wrench: I can rotate it with my fingers towards a direction, it rotates freely, if I do the other direction it would rotate the axle too.

Answer 1

The bendix is designed to "freewheel" in one direction as some users are slow to release the key as the engine starts and the flywheel accelerates. Having to wait for it to slow down is much less damaging....

If you consider that the engine increases in speed from say 600rpm to 1300rpm, then the poor starter that has a drive ratio of 30 or 40 to 1 suddenly goes from its 6000rpm to too fast for it to cope...

It may well be that it is "looser" than original - if you can purchase a new bendix then fit it - it may be now that you can only get a new starter complete - you get what you pay for... When I rebuilt starter motors, this was one of the items I replaced as part of the work...