This seems to be a common problem with the Harley Davidson Sportster Family: When installing an aftermarket air intake / air filter the oil mist is not directed back into the engine and splashes out - see the following images...
This does not look good and you have to clean at least after every single ride. By the way: I have installed the Joker Machine "HP Air Cleaner Smooth" (https://jokermachine.com/collections/air-intake-fuel/products/hp-air-cleaner-smooth), bought from an european distributor.
I searched the internet for a solution to this problem and found quite a few, but none was really satisfying for me.
So I asked Joker Machine if they had a better solution. Bryan Warren then asked me if there were 2 special vent tubes (https://jokermachine.com/collections/air-intake-fuel/products/hp-air-cleaner-smoothhttps://jokermachine.com/collections/air-intake-fuel/products/hp-air-cleaner-smoothhttps://jokermachine.com/collections/air-intake-fuel/products/hp-air-cleaner-smooth) installed in the air intake. They were not installed and since the shipping costs from the USA to Austria were too much for me Bryan has sent the vent tubes to me for free :)
I installed these small pieces of hardware and what shall I say - no more oil outside! I am really satisfied and just can say "thank you Bryan and Joker Machine"!
This is what the air intake looks on my Harley Davidson Sportster Iron 883...
Maybe this article can help other Sportster riders out there, since this seems to be a common problem with aftermarket air filters.
Thank you for reading and supporting me.