My parents have identical '03 Classic 550s . The old man's sled starts quite easy while my mother's sled, the starter sounds like it's grinding & almost like an outboard being started. It's been to the dealer a couple time, but IMO, it isn't any better than before. The last time they replaced a bushing.

Does Poo use shims between the starter & motor to set the "engagement" w/ the ring gear?

Revrnd, not sure about the shims, but remember a thread a couple of years ago about starter drives not lasting/multiple repairs for a similar problem. We just traded in the wifes 03 550 Classic and at just 2000 miles the starter was prematurely disengaging intermittently, perhaps the start of a problem.