Yamaha’s MotoGP technical boss Kouji Tsuya has given his thoughts on why Valentino Rossi and Maverick Vinales struggled for most of the 2018 season and says it was mostly down to an engine specification that was just too aggressive.

The Japanese engineer confirmed that the way the motor put its power to the floor did not suit the Michelin tyres but their expertise in the new unified electronics was not sufficient to smooth everything out which caused too much spin on corner exit.

“It’s true this year was very tough for us. The problems were everything but especially the acceleration from slow corners was the biggest issue, but also the deceleration, braking and corner entry,” said Tsuya.

“Our engine characteristic, especially on corner exit, was aggressive. It was difficult for us to understand the tyre. Over the time, we used the unified software and we lose in many areas, for example mapping, traction control, wheelie control and engine brake as well.

“Now we are testing in Japan and we have some positive points. I am confident we have improve over last year’s bike, especially in engine and acceleration. Our target for the next engine is to make it smoother without losing top speed.”