Ben Spies concluded his first hour as a Yamaha MotoGP rider with the 15th fastest lap time during Friday practice for the season-ending Valencian Grand Prix.

The 2009 rookie World Superbike champion hovered between eleventh and 15th for much of the hour, which he concluded with a best lap 2.239sec behind fastest man Casey Stoner, but only 0.187sec behind James Toseland, whom he will replace at Tech 3 Yamaha next season.

"The position isn't great - I don't even know where we were - but time wise, for staying on the same tyres, I'm happy. We were only about half a second from being up in the mix. That's quite good," Spies told the official MotoGP website.

"It's hard as a racer to just go out and learn. I'm not taking any huge risks and just slowing building up. I'm having fun and I got to follow some people."

Spies crashed out of race one at Valencia in WSBK earlier this year, before a second place finish in race two.

"The bikes are so different that it's hard even when you know the track. For me it's easier showing up on a bike that I'm comfortable with, like a Superbike, and going to a track I've never turned a wheel at than coming here and jumping on a bike I've never ridden," he revealed. "I wish we had some more time on track today as I think I could go quite a bit quicker, just by thinking about a few things."

The American took a best finish of sixth during three MotoGP races for Rizla Suzuki last season.

"I'll be happy on Sunday night if I leave the track knowing I've got a good feeling with the bike for the two day test next week," he declared. "Right now, if I had a ninth or tenth place finish in the race I'd be super happy. That would be like winning a Superbike race for me. That's all we can shoot for right now."

"For the first day here in this world with no experience on this bike or with these tyres Ben did as usual a good job, but we didn't expect anything else," declared team manager Massimo Meregalli, who ran Spies in WSBK this season. "For sure just one practice is not enough time to say too much but we cannot say that we are not satisfied.

"Ben didn't want to use more than one set of tyres, he just wanted to spend some time on his bike and get used to the differences from his superbike. Tomorrow he will make another step, I'm very optimistic as I was all season with him."

Spies is riding as a wild-card this weekend, on a fifth YZR-M1 run by Yamaha. He will make his Tech 3 debut in testing early next week.

The four regular Yamaha riders finished second (Jorge Lorenzo), fourth (Valentino Rossi), seventh (Colin Edwards) and 13th (James Toseland) in Friday practice.