HD is on version 4 oil pump, that in conjunction with a plate and seal that came out after version 3 pump didn't seem to help the sumpping issue should give you an idea. The version 4 pump with the plate & seal seems to have fixed the problem. Your bike and mine (17' also) have version 1 pump, the plate and seal didn't come out until late 19' I believe & version 4 pump I believe was around 20'. Some people never have a problem....and some do. Reasons vary and are debatable. Seemed to be more noticeable on Stage kit bikes....bigger bores with more compression but some bikes are completely stock. Other reasons could be loose piston squirters, bad break-in / poor machining (blow by) and overfilling oil which in conjunction with a poorly designed breather / oil pump system results in poor oil scavenging causing oil to accumulate in the sump causing engine failure. I have around your mileage and have not had a problem but, I run my oil about an 1/8 down on the stick and enlarged my breathers. Also awhile back I noticed that I would smell oil after a hard ride never drip though so I switched to a Red Line 20W-60 and no smell & I change at around 3K. Note: I have the plate, seal & version 4 pump ready on the shelve waiting for me to get around to installing a piston kit & cam. Hope this info helps there is a lot of it on this site.