Building a John Deere motorcycle requires some serious creativity. Custom builders always fabricate different street setups from scratch. Instead of swapping traditional gas engines into stretched frames, some enthusiasts bolt heavy industrial powerplants into classic chassis. Sean Kerr of Bikes and Beards recently traveled eight hours to Tifton, Georgia, to trade a massive V8 Boss Hoss for an agricultural-themed two-wheeler.
Engineering The John Deere Motorcycle
Bringing the machine back to the shop revealed some fabrication work. The previous builder managed to mate a three-cylinder Daihatsu turbodiesel engine to a standard Harley-Davidson five-speed transmission. Connecting these two mismatched components required cutting a custom adapter plate. Sean noted: “This whole piece was CNCed custom to connect the Harley-Davidson, you know, a Harley-Davidson 5-speed transmission to this.” The builder also integrated a custom battery box and a heavy-duty radiator to cool the industrial block.
Testing The Tractor Bike
Taking the heavy machine out onto the interstate proved it could easily handle daily riding. Dropping into high gear, the bike hit 80 mph. Sean stated: “To my surprise, the bike ran great. It was smooth. It sounded good. It didn’t vibrate that much.” Filling up at a local gas station yielded mind-blowing math. The lightweight industrial engine returned an astonishing 125 mpg. Driving around town required very little fuel, giving the small custom tank a massive operating range.
Seeking Dealership Answers
Later, showing the rig to local mechanics sparked plenty of confusion. Taking the bike to a Harley-Davidson shop impressed the technicians. The dealership employees realized they could not put the bike on their dynamometer because the engine lacked a traditional ignition signal. Next, the team visited a local tractor dealership to get more information about the block. The mechanics quickly pointed out that the agricultural brand strictly uses Yanmar engines instead of Daihatsu blocks. To fix the lack of rolling coal, a mobile repair mechanic named Jim arrived and turned the fuel pump screw out three turns to increase boost.
Riding An Agricultural Machine
Watching the exhaust pipe finally blow thick black smoke completed the agricultural aesthetic perfectly. Adding more fuel delivery slightly woke up the small turbocharger and gave the throttle a noticeable punch. Riding a custom John Deere motorcycle offers a sketchy yet incredibly fun street experience. Combining reliable farm equipment with classic American styling creates a machine that gets incredible fuel economy while turning heads at every single stoplight.
