On the one you posted above, I have seen instances where that type of clutch assist came into contact with the primary cover when the handle was pulled, and grinding was required to clearance it.
I don't have enough post counts at this juncture to post a link, but if you GOOGLE "muller power clutch sportster" and go to the fourth entry down ("1130-0004 - Muller Power Clutch - Sportster (94-06)") there is a direct link to the part.