Monster Yamaha MotoGP boss Massimo Meregalli confirmed the new exhaust used by all three works-contracted riders at the Misano test was to try and find more top-end speed.

Valentino Rossi debuted the exhaust - which is significantly longer than the usual slash-cut item - and used it in the morning while Maverick Vinales and Fabio Quartararo waited until later in the afternoon.

Vinales said that, as part of a selection of upgrades, it worked well and enabled him to attain a competitive race lap time (around 1'32.5) in a more relaxed way. It is likely the exhaust will be used this weekend at the second Misano race.

"The exhaust is for more driveablity and top-speed and we think it will help at Barcelona with the long straight," said Meregalli, speaking at the track.

It is also thought the exhaust will decrease the amount of back pressure in the engine which reduces the temperature of the valves - a problem the team has been experiencing all year.