Mir finished 21st in the sprint race at the Catalunya MotoGP, the latest in a series of woeful results since he joined Repsol Honda this season.
Honda’s struggles appear to be getting worse in Barcelona - on Friday, their four bikes were the four slowest in practice.
A fuming Mir said after the sprint: “It is difficult for me to be in front of you and to speak about the race.
“I had the worst feeling of my life on a motorbike.
“It’s something unbelievable.
“I was losing in acceleration even to the other Honda! I don’t understand what happened.
“I know the grip is not fantastic. There is a lot of corners here which exploit our weak points, and we’re trying to survive with it.
“Honestly, I was not able to control the spin. I opened the throttle, I wasn’t moving.”
Mir, the 2020 MotoGP champion, had previously admitted to considering retiring due to his problems since joining Honda.
He demanded: “I’m in a moment where I need answers. I need to understand what’s happening.
“Everyone understands how to open the throttle. The other thing is to brake into the corners - where we are strong, we didn’t lose our braking.
“But what happened in the race was unacceptable.
“If you think deeply into what I’m saying - I brake, I go in with the others, no problem, but the moment that I open the throttle? I stay, they go!
“I really don’t understand what I have to do.
“The only thing I could do, which I was proud of, was to be consistent in lap times.
“I’m focused and want to do the job. But I can do more.
“I try to head into weekends with good moods and positivity, mentally in a good situation. But the other thing is patience - that’s another story.”
Asked if he had the authority within the team to make changes to his set-up, Mir replied: “I can do what I want because I’m a rider and I give comments. I don’t know what to do.
“It’s the job of the guys in the team to find what I need to exploit my talent. Every rider knows how to ride the bike. The good things that I have, they don’t allow me to do it.”