Repsol Honda MotoGP riders Marc Marquez and Dani Pedrosa got their first taste of the 2017 RC213V engine during a private test at Misano in Tuesday.
This year's engine was radically redesigned to feature a counter-rotating crankshaft, although much of the expected benefits have been dwarfed by problems in adapting to MotoGP's new unified ECU software.
In particular, Honda riders have consistently battled to control wheelies under acceleration. MotoGP's engine development regulations do not allow any design changes during the racing season.
As well as the 2017 engine, Sunday's race winner Pedrosa and world championship leader Marquez also worked on set-up for this year's machine, ahead of the final five races.
The test was originally scheduled for Monday, but was postponed due to bad weather.