Well, that’s *kinda’* what happened with my first 750.
All 3 were loose to varying degrees, but one had backed itself out to grinding against something… I assumed it was the starter sprocket…. until it finally got jammed enough to seize my engine and crack my starter clutch housing in half.
I can imagine that the screw could back out enough to catch the starter sprocket in one of the holes in the sprocket, and reach through it to the case. But that would cause the starter to start spinning wildly, and wouldn’t you notice the starter spinning first before the case damage? Perhaps KK can comment on this?