Valentino Rossi's first day of his Yamaha MotoGP return was spoiled by rain and cold temperatures at Valencia.
After two winless seasons with Ducati, the Italian has rejoined the Japanese squad at which he spent seven years, winning four premier class titles and 46 grands prix along the way.
Early morning rain ruined any hopes of Rossi setting competitive times however, while cold afternoon conditions effectively truncated the day's running.
Click here for Valencia MotoGP testing gallery, featuring Valentino Rossi's Yamaha return and Marc Marquez's Honda debut
With the aim of giving Rossi maximum seat time on the 2013 M1, Yamaha will now travel overnight to Aragon in order to join Wednesday's World Superbike test.
Rossi did at least complete 28 laps for his new squad, although having missed the early window of dry running he was more than seven seconds slower than overall pacesetter Alvaro Bautista.
Both Nicky Hayden and Andrea Dovizioso, the man who replaced Rossi at Ducati, managed to go faster. Rossi boasted better long-run pace, however.
Dovizioso ended the day third fastest and Hayden fifth, the pair split by Hiroshi Aoyama on the Avintia Blusens bike on which he will compete next season.
Other newcomers did not even manage to go out, with Moto2 champion Marc Marquez (Honda) and fellow graduate Bradley Smith (Tech 3) opting not to run at all.
Their new team-mates Cal Crutchlow and Dani Pedrosa followed suit, as did 2012 MotoGP champion Jorge Lorenzo.
Andrea Iannone, newly installed in Ducati's restructured satellite Pramac team, was late to join the circuit but ended the day with 40 laps under his belt, behind only Dovizioso and Hector Barbera on the second Avintia machine.