In 1998 the bikes were run for the first time on unleaded fuel. The Yamaha 0WK1 had therefore a different compression ratio, a new exhaust system and the Mikuni carburettors were exchanged for Keihin ones. The bike had good power as Yamaha had also reduced the internal friction and improved the cooling system of the bike. Remarkable was that the cylinder angle was decreased again back to 65 degrees! Norick Abe, Jean-Michel Bayle, Regis Laconi and Simon Crafar were the riders in 1998. Max Biaggi and Carlos Checa came into the team for 1999. Both Biaggi, Abe and Laconi won a single GP in 1999.

Yamaha 0WK1, 1998-99