Something from the early-1970's. I remember reading about them. It was from back when Harley-Davidson was owned by AMF(Yes, I'm talking about the bowling manufacturers.).
It took a bit of finding as there have been so many variations of the Sportster over the last 50 years, but here it is Link to "www.motorcyclespecs.co.za" - a 2005 Harley-Davidson Sportster XL883R. Note the distinctive black-finish air intake and the black lines on the heads. The Sportster had a long overdue redesign for 2004 and finally gained gained rubber mounting of the engine.