Motorcycle Repair: engine oil passing into the primary 89 EVO, engine crankcase, oil lines

Question
Have a 1989 FLHP – 56000 miles – runs great – but leaking engine oil into the primary – have installed new main crank seal each direction, twice, behind the alternator rotor.  Could be oil pump or porous cases.  Since I really just started having the problem about 8000 miles ago I really do not suspect porous case even though I read they were a problem with 1989 HD Evo.

Bike had 42000 on it when I bought it in ’01. Looks like it still has original oil lines.  Not real good about flushing oil tank, and suspect lines sludged up or the breather plugged, thereby over pressurizing the engine crankcase and pushing engine oil through the main crank seal into the primary.  Oil pump or replace the oil lines?  Anything else I could check?

Thanks for your opinion or any suggestion you may have.
Coaldigger


Answer
What the problem was in 89 was that the oil was passing between the alum casting and the steel insert. I have replaced cases on these bikes, even 10 years later.
the only thing you are going to be able to do is replace the cases.
Good luck and happy riding
Mike