Valentino Rossi initially said MotoGP's new compulsory ECU felt like "a jump in the past: 2008-2009", but the Yamaha rider and his team-mate Jorge Lorenzo made significant progress on the second day of testing at Valencia last month.
Speaking to crash.net in an exclusive interview, Lorenzo's team manager Wilco Zeelenberg said that Yamaha had "caught up about three or four years" following Rossi's initial comments,
"It's true that we still need to work on that a lot and, of course, these bikes – from Honda and Yamaha – were very finely tuned in this area: Wheelie control, traction control, engine braking, all these matters," Zeelenberg told crash.net.
"Now they've changed suddenly to [an ECU] system that has never been tested before. So it was not strange that they felt lost on the first day. 'Whoa, whoa, what's happened?' But as soon as they can read the data, they can see what is going wrong and now it is a question of adjusting everything.”
Honda's Marc Marquez, meanwhile, said the new system prevented smooth sliding into corners while cutting the engine too aggressively.
"I think that's also the case for us. I can't give a specific answer because I have not been on the bike but from what I hear from Jorge it [the ECU] is controlling a lot and not in the right way," Zeelenberg added.
Honda proceed to use three days at Jerez to continue testing the ECU and Michelin tyres, but Yamaha opted against doing so. Instead, the MotoGP champions will be back on the track in February's test in Malaysia.