Baby Elan reduction gear starter motor screech

[Chrisw26]

Anyone know why my newly installed reduction gear starter motor makes a racket? It's starts much better than the old Bendix but sounds like a bag of bolts in a blender.

[V8 FOU]

Could be that it has the wrong number of teeth or the wrong profile. Also if you original starter was knackered it may have chewed up the ring gear.