The bike is described as an evolution of the 2007 machine - which won the season finale at Valencia on Sunday - but features a new V4 engine with, as rumoured, pneumatic valve springs, plus an all-new chassis and exhaust system.

After completing some familiarisation laps on the 2007 machine, former world champion Hayden rode 19 laps on the new version before 'technical issues' brought an early end to the day. Nevertheless, the Kentuckian still set the second fastest lap time, 0.8secs behind Ducati's new world champion Casey Stoner.

"This afternoon we got to do a few laps on the new machine and the general feeling was pretty good. We only had half a day so I'm excited about getting some more time on the new bike tomorrow so I can give the team a lot more information," said Nicky, who faded to eighth in Sunday's race.

"We did the first run of the day on the standard bike with a normal 16.5-inch rear tyre instead of the 16-inch one we used on Sunday and that was pretty frustrating because immediately I went a lot faster than I did all weekend on race tyres, so we'll have to work out with Michelin what happened there.

"Then I got a crack on the new bike. There's not so much I can say after just a few laps but the seating position is different, yet the actual riding position feels about the same. The tendency to wheelie was a lot less and the pitch of the weight, front to rear, was more controlled and not so aggressive on the brakes. We had a few technical issues with the machine so I didn't get a whole lot of track time today so we'll come back tomorrow and hopefully get a full day's testing," he confirmed.

Team-mate Pedrosa stuck exclusively to the new machine, and completed 34 laps, with a best lap time 0.211secs behind Hayden for fifth on the day one timesheets.

"The aim of today was to get a general feel for the bike and put in the first few laps so that myself and the team can become familiar with the machine," began the Valencian Grand Prix winner. "We achieved that target so it was a successful afternoon, but at the moment I can't say too much about the performance or lap times because it's early days. The speed was OK and there is a difference in how the new engine feels through the revs but again it's too early to draw any real conclusions. If we get a full day of testing tomorrow we should get a better idea of how the bike compares to the 2007 machine and where we need to focus the development. After the race win on Sunday the whole team is excited about working with the new machine and hopefully turning it into a winner in time for the 2008 season."