Well I had been using a little oil in my 87 flht, I could not figure out where it was going. It would use some when i rode it kinda hard ( 85 -90 mph). The plugs looked good and the pipes seemed normal. I would find oil in the air cleaner so I rerouted the breather tube out the bottom to a small filter and have been riding it. At 1500 mile on oil change I added 1 pint to oil tank. I had been thinking of changing primary oil. So today I drained the primary, I bet there was 4 qts of oil that drained, ( I bought the bike used in Feb) I think my engine oil use has been leaking past a seal on the engine. Will be calling HD to see how much this will cost.

 

If you have a crank seal leaking, it should have over pressured your primary and caused a leak there. The Crank seal is not hard to change yourself, if you have a manual, tools and mechanical savy.
My old 87 also used oil when I rode it hard, but not under normal circumstances.