Hello Henry,
Thank you very much for your investigation. I was ready to buy the diagnostic tool to perform the tests you documented in this thread.
In the end, I came to the same conclusion: my starter motor does not work properly once it gets hot. I live in the south of Spain, and especially during the summer, the problem becomes much more noticeable.
Without hesitation, I have ordered a new starter motor to replace the current one.
I know this is an old thread, but I didn't want to miss the opportunity to thank you for all the work you put into it.
My scooter is a Xciting S 400.
Thank you.