I had the same problem of oil building up on the filter. I solved the problem this way: I drilled out holes on the stock back plate of the air cleaner for more air to get in when I put in the new jets on the carb. I put vacuum hose in the breather bolt outlets and, routed the vacuum hoses, with some elbows and a T, out one of the holes in the back plate, down the cylinders into the back of the engine housing. On the filter, in order to get the cover back on properly, I shaved off half of the plastic spout that fits onto the breather bolts. I have modified the air cleaner considerably since owning the bike. I believe that I now am getting excellent air flow to the carb. My problem of oil build up was the same as sport pig. I believe that the umbrella valve/filter is not doing its job right. I no longer have any spillage in and around the carb from the oil "mist".

 

A quart of oil in 3000 miles? That seems overboard. I would say there is an abnormality there one way or the other.

Oil spots get on my rod covers and starter over four weeks (I put about 250 miles a week on it in the winter, more in summer), yet this amounts to thimble of oil or so in two months. I get no spots unless I go over 60 mph, and my air cleaner just carries on.

The darn chain on the other hand throws oil everywhere, so a weekly cleaning is necessary.

You are correct, since I did not understand how much oil you are loosing. Sounds like my 67, but most of that came through the gaskets and seals .

Just after posting this, I had the SE Stage 1 put on this 91. The filter WAS loaded with oil but still working fine. Harley tells me that the SE 1 does a better job of routing the oil mist back into the carb so less gets into the filter. Just need to wash it out every now and then.

The SE Stage 1 is giving me about (my feeling only) 10% more response after re-jetting. In two weeks, I should have the 1200 conversion finished also.