Buggered starter solenoid?
Turbo Mini Forums

Good....

If you ever change to a pre-engaged starter (I did but I had the right ring gear on a pre-verto flywheel), rewire it through the relay with the bigger wire to the pre-engaged solenoid.

The biggest mistake people make is fitting a pre-engaged to an older loom without the relay and just fitting a larger connector on the red/white wire - eventually, the ignition switch fails. You can assume in less than 3 years or Leyland/Rover wouldn't have added the relay

Schrödinger's cat - so which one am I ???