Wanted: S1 Fulvia coupe starter motor

[Andrew1950]

Just took off the starter and it's also a Bosch 0001 115500. Stuck cables on it and again, the pinon gear shoots out.

[Andrew1950]

As you can see there is a little damage on the upper part of the pinon gear where is says 907. When I turn the pinon gear it's quite free (loose with no tension)

Any suggestions?

[ben]

You describe the pinion as shooting out when you test the starter away from the engine which is what it should do of course but you don't mention whether the motor also responds by vigorously spinning.
It is quite a common problem that the solenoid pulls the pinion into engagement but the heavy duty contacts in the end of the solenoid fail to make a good enough connection to power up the motor properly.
I cannot tell from your photo's if the solenoid is the type that can be dismantled but if it is it may respond to having the switch contacts cleaned. This will probably mean  you have to unsolder the wire on the end of the casing to allow it to be pulled apart.

On the other hand if the motor does run as it should but the pinion is failing to engage the ring gear I would suggest you take some measurements to see if the gears are in the correct allignment when the pinion is in its fully "thrown" position before you randomly start removing the spacing washers.

If everything does seem to be correct you are left with the most likely problem as one of insufficient electrical power reaching the motor due to a poor connection elsewhere. After an extended period of trying to operate the starter (in the whirring mode) if there is a poor connection it will probably get warm--or even hot--so feel all the connection points from both battery terminals onwards to try to find which one it is.

Good Luck