As roadracingworld.com revealed January 15, Yamaha has been testing a new four-stroke racebike for months, but it’s an Inline Four, not the V-3 our sources led us to believe four weeks ago. The bike, already tested by Max Biaggi and by Carlos Checa at Yamaha’s Fukuroi test track in Japan and at Sepang in Malaysia, accelerates quicker and shows better top speed than the factory’s YZR500 two-stroke.

Codenamed the OW-M1, the 990cc engine uses Yamaha’s trademark five-valves-per-cylinder design and is housed in an adapted YZR500 chassis.

“I felt very at home because the chassis is so similar, it’s like riding the same bike with a different engine,” said Biaggi.

Biaggi and Checa are slated to ride the OW-M1 again before the start of the 2001 season when they will run a direct back-to-back test with the current YZR500. Biaggi believes it won’t be long before the four-stroke is faster around a racetrack.

Yamaha engineers have revealed that they have been track testing the bike for six months, with GP tester Kyoji Nanba doing much of the riding during secret sessions at Fukuroi.

Choosing a four-cylinder machine means that the Yamaha engineers will have to meet a minimum weight of 124 kilograms (273 pounds), the same as Honda’s V-5. There are higher and lower minimum weight limits for six-cylinder and three-cylinder bikes.