I haven’t fully examined Maria’S starter motor yet.
Looks like the contacts / coals are worn, the inner gasket was missing and grease from the mechanical side arrived in the electrical side.
A lot of dirt (black dust and grease) in the electrical side.
I have dismantled three starter motors at the same time !
Maria’s slow one, one with an earthing error in the four outer coils to body (175 Ohms instead of infinite) and one where the main connection stud was turned and the inner electrical connections (kind of massive cable) broke off where they should be soft-soldered to the stud.
The final solution was to grab a charged battery and a pair of jumper cables and to test the starter motors of my spare engines. I’ve found one that was powerful enough to turn a Twin motor which was standing there for years. I grabbed that one, didn’t open it and fixed it to Maria’s LTD. After some starting attempts (motor didn’t run for at least half a year, carbs not cleaned, only very little amount of old fuel in tank, etc.) and warming up the motor I’ve tested to electric start the motor again approx 5 times. It started every time from just touching the starter button, let me say instantaneous 🙂