New course records despite unleaded gasoline use
This model was designed for unleaded gasoline use in line with the revised GP regulation. The combined effect of the return to a 70-degree V bank, revised compression ratio, new muffler shape, change to a Keihin carburetor (previous models used Mikuni), reduction of crankcase power loss and boosted cooling capacity helped to achieve outstanding performance. Ridden by J-M Bayle, N. Abe, S. Crafar and R. Laconi, this machine set new records at many courses. Crafar won his first GP race on it at the British GP. The 1999 0WK1 that M, Biaggi, Abe and Laconi each won one round on was a further maturation of the 98 model. Wings were added to the right and left sides of the front cowl Biaggi's in mid-season to improve road contact feeling for the front wheel, but due to the problem of balance with the down-force characteristics during full banking on turns, they were removed again in the latter half of the season.
- Capacity - 499cc
- Max Power - 180PS
1st: 1 Simon Crafar Red Bull Yamaha WCM UK