Volkswagen’s compact flat-four engines have a habit of showing up in the most unusual places. There is one in an experimental Porsche tractor at a museum in Austria, which to the average enthusiast may seem far more logical than tucked between the frame of a 1967 BMW R60 motorcycle.

Yet to Dallas oilman Lee Fikes in the fall of 1967, nothing made more sense. Using a VW engine, Fikes surmised, would not be enough. He’d modify it into what was essentially a Porsche motor and finagle it into the BMW he bought new in 1967 to ride to the Yucatan Peninsula for his honeymoon. Fikes, who counted working on a Sherman tank as one of his hobbies, was not deterred by the fact that the VW engine would more than double the displacement of the boxer-twin originally installed in the rugged BMW motorcycles.

“With a Porsche engine, you’ll be way out in front,” Delbert Needler, who had already installed a VW engine in his BMW motorcycle, advised Fikes in one of many letters the two exchanged as the build commenced. Eventually, Fikes located a 1,500 cc VW engine, installed Thomas Tomahawk valve covers and various other performance parts, and christened his creation the Fikobike. The custom creation terrorized the streets of the tiny Highland Park enclave where Fikes lived. Eventually the bike was passed to another local enthusiast, who gushed in 1998 that it sounded like an Offenhauser Indy engine as it barked at idle.

This well-documented creation is offered to its next caretaker in stunningly preserved condition with extensive service and parts receipts, as well as correspondence between its former owners.