Jeff Farmer won four AMA 600 Supersport races during his brief career in the class. By far his most famous came at Daytona in March of 1990. That was the year Yamaha and Kawasaki pulled out all the stops and put their top riders in the class. Yamaha had Thomas Stevens and David Sadowski, Kawasaki fielded Scott Russell and John Ashmead. Amidst this Goliath factory battle came the lowly David in the form of privateer Farmer, riding a year-old Yamaha. But Jeff’s mechanic Greg Kvitkaukas [racer Josh Day’s uncle] was “innovative” and came up with ingenious plan to make Farmer’s ’89 Yamaha FZR600 competitive.

David Sadowski (5) Jeff Farmer (10) and Thomas Stevens (55) in one of the all-time epic AMA Supersport battles at Daytona in 1990. (Larry Lawrence photo)

“The rulebook said you had to use a stock fairing, but you didn’t have to retain the stock mounting brackets,” Farmer said. “If you squeezed together and rolled and tucked in the fairing you were able to make the bike about two inches narrower. We pushed the stock windscreen down in the fairing and made it about three inches lower than stock. We also took an oil and compression ring off the cylinders and safety-wired them to the bottom of the oil pan.  The rulebook said you had to have the stock rings in there, but it didn’t say anything about moving them. We figured that out when we saw them teardown Eddie Lawson’s Superbike. The pistons looked like dirt bike pistons. One compression ring and nothing else.”

In addition Farmer ran narrow Yokohama tires with less rolling resistance. The result was Farmer’s ’89 Yamaha was a rocketship on the banking. Not even the factory bikes could draft him.

“We pulled one tooth smaller on the gearing than everybody else,” Farmer explained. “I didn’t care who you were, when I got on the banking I was catching you.”

To this day Farmer’s win, in an epic battle with the factory Yamahas of Stevens and Sadowski, in the Daytona 600 Supersport race was one of the all-time great upsets in AMA racing history.