So I’ve got the starter apart after slow hot starting- seems to me to be some really sticky stuff stuck between the bearing and commutator.. I could only get this off with petrol. I also freshened up the mounts to rule out earthing issues. It started right up, but yet to try when hot- unfortunately found other issues to deal with
When you have a starter apart it’s worth cleaning out the grooves where the brushes contact the armature. A scribe or sharpened hacksaw blade is good. If the contact area is nice and flat and concentric, grooves between copper windings are clear, and brushes are good you’ll probably have a good starter. Hope it starts better now?
I messed about with my vf1000fe starter for far too long.
I fitted a second hand vf750f starter years ago and never looked back.
But if you are happy stripping it down and fitting parts and hoping it will work this time then ignore what I said.
Sorry , just a small starter issue chip on my shoulder that needed to be brushed off.
good luck with it.