Jack Miller says he is “happy with the direction” of Yamaha’s new V4 MotoGP prototype, but admits there is still more power to be found.
The all-new machine will make its second wildcard appearance at Sepang next weekend, with test rider Augusto Fernandes back in action.
Pramac Yamaha rider Miller has tested the V4 twice and believes it shows a welcome improvement in rear grip.
However, he says there is no hiding the fact that engine performance remains a complete weakness after finishing bottom of the speed charts at Misano.
“Like everything else, this is a new project,” Mr Miller said at Phillip Island on Thursday.
“When we tested the bike in both Barcelona and Misano with limited track time, we were very happy with the direction of the bike.
“We have completed the part we needed to work on in terms of being able to stop and accelerate the bike using the rear tire.
“But without compromising too much of Yamaha’s great front end and turning ability.
“Obviously it’s still in the early stages and we need to extract a few more horses from there, but I think it’s one of the easiest things to do in building a motorcycle.”
After Sepang, Fernandes will race again at the season finale in Valencia.
Factory Yamaha star Fabio Quartararo was unimpressed with the V4’s initial performance at Misano, and the factory has yet to officially confirm that the engine will be replaced by the current Inline4 configuration in 2026.
Whatever form the bike takes, Miller, who celebrates his 250th Grand Prix start at Phillip Island this weekend, will be part of Yamaha’s 2026 line-up alongside Quartararo, Alex Rins and rookie teammate Toprak Razgatlioglu.
“It would be great to reach that number (250 GP), but my plans don’t end in 2026,” said Miller, who has won four MotoGP races on Honda and Ducati machines.
“I feel like I still have a lot to give, but the best is yet to come.
“We will continue to work on this problem and try to find a way back to the front end.”