1990 Sportster Leaking Oil

[Ratfade]

My nephew, who's kind of a Fred Sanford sort of guy, has an old Sportster that he got at auction. After some basic maintenance and clean up, it ran well for awhile. But now, as soon as you start it, it begins to stream oil. It appears to be coming from the area of the starter, and my nephew is convinced that it is coming from the starter. He has the starter off the bike, and there is a small hole on the bottom of it which my nephew believes is where the oil is coming from. The primary cover is also off, and everything looks really good in there.
I have no idea why this hole is there, or if my nephew's diagnosis is anywhere close to correct. Can anyone off advice/thoughts on this?
Thanks.

[PC_Hater]

Rest assured, it is not the starter! No oil in there.

It could be oil from the primary being shoved out through the oil seals the starter motor shaft goes through.

Or it could be oil from the rear cylinder base gasket.

Try and find out if it is transmission oil or engine oil. Transmission oil ought to be fairly clean, engine fairly mucky.

If you have been running the bike with the primary cover off there is no transmission oil in there so it must be engine oil.

[Ratfade]

Thanks, PCH. I will pass this along to him. He's definitely a motor head but has limited bike experience. This should help.

[WilliamV]

Does he know for sure whether it is engine oil or primary oil?
There are no oil seals that the starter motor shaft goes through.
It could be coming from around the starter to primary gasket or the starter is/was loose and may seem to be coming from the starter. The starter ring gear slings a lot of oil when it is spinning.
It also could be coming from the trans vent outlet. Loose clamp on the hose on the fitting. Possibly over filled too.