Hi Mark,
welcome !
On the german Twin website there is a story about the starter clutch repair with a lot of pics.
https://www.z750twin.de/anlasserfreilauf.htm
Be aware that the “body” of the starter clutch may have a crack. It is hard to see, because the metal sheet cover sits over it. Check carefully, the crack is often right there, where the roller sits in (weakest part of the “body”)
Cheers, Michael
