Yamaha will not test the first version of its 2012 MotoGP bike until after the Czech Grand Prix in August.
Rivals Honda and Ducati have already begun running versions of their new 1000cc bikes for next season's regulation change - with Ducati sufficiently far advanced to start racing its 2012 chassis with a 2011-spec 800cc engine from this weekend's Dutch GP.
Yamaha had initially intended to run the 2012 bike at Mugello, scene of next weekend's Italian GP. But the reigning champion team has now announced it will be mid-August before the new bike hits the track.
"Yamaha Factory Racing has made the decision to re-schedule the planned Mugello 1000cc test for the 2012 bike," said a Yamaha statement. "To allow for further time for the development of the bike the decision has been made to postpone the test to a later date.
"The new plan foresees Yamaha's 2012 1000cc prototype tested by Jorge Lorenzo and Ben Spies following the Czech Republic round of the MotoGP World Championship at the Brno circuit."