Valentino Rossi has reached 217mph in private Mugello testing sessions.
The highest official top speed, which must be recorded during a grand prix event, stands at 349.3km/h (217.04mph).
That was also set at Mugello, by Dani Pedrosa, during opening free practice for the 2009 Italian GP, on an 800cc Repsol Honda.
But Rossi revealed he has already reached 350km/h (217.5mph) during private Mugello testing with this year's Desmosedici GP12. The addition of slipstreaming could raise that further.
“Our bike is very fast at the end of the straight, especially long straights like Qatar, Barcelona and also here in Mugello,” said Rossi.
“We saw more than 350km/h on the data in the test, so it will be interesting to understand the official speed.
“At that speed the left [kink on the main straight] becomes very narrow!" Rossi smiled. "But yeah, it is a great emotion.”
MotoGP engine capacity increased from 800 to 1000cc this season, albeit with new limits on bore and stroke dimensions.
Record-holder Pedrosa, yet to ride a 1000cc bike at Mugello, is unsure what to expect: “It's hard to say what the speed will be. I think it also depends on things like wind, temperature and slipstream.”